audio and video signals in a dynamic movement in light of changes in tone amplifier specific wirememory flyer

X . I  Signal propagation Audio (Sound Waves)



Audio interpreted as sound or sound reproduction. Audio signal or sound waves are waves generated from an object that vibrates at audio frequency range (it can be heard by humans). The human ear can hear sounds between 20 Hz to 20 KHz (20.000Hz) corresponding audio signal limits. Because, basically, the audio signal is a signal that can be received by the human ear. Figures 20 Hz as the lowest-frequency sound that can be heard, while 20 kHz is the highest frequency that can be heard. 

Sound waves vary as the pressure variation intermediary medium such as air. Sound created by the vibration of an object, which causes the air around it vibrate. This then leads to the air vibrations of the human ear drum to vibrate, which is then interpreted by the brain as sound. Illustrated in speakers create sound waves. Sound waves travel through the air mostly in the same way as water waves travel through the water. In fact, because the waves are easy to see and understand, is often used as an analogy to illustrate how the propagation of sound waves. 


Black spot on the image above shows air molecules. As loudspeaker vibrations, causing the molecules around it vibrate in specific patterns indicated by the waveform. The air vibrations cause the eardrum to vibrate listeners with the same pattern. Air molecules actually walk from the loudspeaker to the ear. Each air molecules move on a small distance as vibration, but the resulting molecules vibrate all affected runs adjacent to the ear. All waves must have had three important properties for audio work includes: wavelength, amplitude and frequency. Sound waves can also be expressed in a standard graph x versus y as shown below.  


X . II Graph Signal Audio (Sound Waves)  


   

Figure stretcher makes it possible to visualize the waves with mathematical point of view, known as the yield curve waveform. F = \ frac {1} {T} wave period (T): The distance between the point of the wave and the equivalent point in the next phase. Amplitude (V): The power or wave power signal. High waves that can be seen as a graph. The waves were higher interpreted as higher volumes, so-called amplifiers for devices that add amplitude. Frequency (F): The number of vibrations that occur within one second. Measured in hertz, or cycles per second. The faster the sound wave vibration, the higher the frequency. Higher frequency interpreted as a higher path. These sound waves propagating in air, or water, or other material. The only place where the sound can not propagate is space vacuum.  


     


X . III  Sound Wave Propagation (Audio)  


Sound waves have a vibration that can propagate in the air, or water, or other material. The only place where the sound can not propagate is space vacuum. These sound waves have valleys and hills, valleys and hills of the fruit will result in one cycle or period. This cycle takes place repeatedly, thus forming the frequency of the sound waves.  


Sound wave propagation is the process of sound propagation in wave propagation media (air, water, solids and other materials). Sound waves travel in air approximately 344 m / sec (3 fo 4 fo 4). This speed is relatively small depending on temperature and under normal room conditions can be ignored. The wavelength of sound is the distance between successive repetitions of the waveform as the sound travels through the air. Wavelength is expressed in the following equation: Wavelength = speed / frequency  


     

Where: C = speed of sound wave propagation m / s f = frequency (Hertz) λ = wavelength (m) The period (T) is defined as the time required for one cycle of the waveform T = 1 / f. For f = 1kHz, then T = 1/1000 = 1 ms or 0,001 seconds, and λ = 344/1000 = 0.344 m. The lowest sound that can be heard has a wavelength of 10 m and the highest having a wavelength as short as 20 nm. The scope is quite large and we will see this behavior stern voice.    

X . IIII   Basic aspects of Sine Waves  

 
     

Sine wave form is the basis for the formation of all the speech signal and music (sound waves). The image above shows the basic aspects of the sine wave. Waves can have the same frequency, amplitude and phase angle of the two can be different. The amplitude and phase angle relationship between the sine wave is determined how the combination of acoustic and electric.  


X . IIIII   The combination of Sine Waves  


If two or more sine wave signals have the same frequency and amplitude are added, the result signal has the same frequency and amplitude dependent phase relationship of the original signal. If there is a phase difference of 120 °, to produce the same amplitude as one of the original signal. When combined in the same phase produces twice the amplitude of one of the original signal. For the phase difference between 120 ° and 240 ° generates a signal which always has an amplitude of less than one of the original signal. If both signals have a phase difference of 180 ° will definitely produce a total zero.   


Image Combination Two Different Phases Sine Waves  


    


In the electric circuit is difficult to maintain a relationship phase is identical for all components of the sine wave signal is more complex, except for certain cases where the signal is combined with the phase relationship of 0 ° or 180 °. Circuit which maintains a special phase relationship (eg 45 °) beyond the width of the frequency range is obviously complex. Thus wide coverage, all of which passed the phase shift network used in the acoustic signal processing. When associated with complex signals such as music or conversation, one thing that must be understood that the concept of coherence. An electrical signal is fed through a high-quality amplifier. A small portion of the distortion signal, the output signal is a replica of the input signal, except for the amplitude. Both signals, though not identical, are said to have coherent (integrated) high. If the signal is passed through an amplifier that is not good, it will get the substance of the differences between the input and output, and the coherence of the amplifier will not be good. If compared to signal differences in total, there are similarities randomly and both can be said to be incoherent.  



Image Combination Two Random Noise Generation  


   


When the two signals are not coherent added, the price of the rms signal generated can be calculated by adding the relative power of the two signals, better than its voltage. For example if the combined output of the noise generator separately, each generating output 1 volt rms, the measurement will produce 1,414 volts rms are shown in the image above. 
The combination of Sine Waves PendingIf the two signals coherent wide coverage, combined with the specifications the time difference between the two is better than a fixed phase relationship. Some frequencies will be added and others will be delayed. A signal to be delayed and combined with the original signal to produce the form of comb filter, which enters the frequency response of the signal as shown in the figure below. Delays can be achieved through the use of electrical network delay or skip all signals with a digital processor. In connection with an acoustic signal in the air, there is no way to avoid the effect of the delay due to the relatively slow speed of sound. 

Image Combination Signal Delayed  


 

X  . IIIIII  Characteristics of Radio Frequency (RF) With Frequency Modulation (FM)  


To be able to transmit data over the air requires a device that can perform the laying process digital data to the carrier wave (carrier). Radio Frequency Data FM transceiver is a device that can transmit data via the air (wireless). The device can perform the laying process digital data to a carrier wave with a higher frequency and then emitted into the air by the transmitter. At the receiver, the carrier wave containing digital data received by Radio Frequency FM receiver section.  


 

On the delivery of information, FM systems are widely used compared to AM system. When compared with systems AM, then FM has several advantages including.  


More resistant to noise
 
Frequencies allocated to FM broadcasts are in the frequency range of 88 MHz - 108 MHz, where the frequency region is relatively free from interference either from the atmosphere or interference that is not expected. The range of modulation system is not much when compared to the AM modulation system where the wavelength is longer. So that the noise caused by a decrease in the power level has almost no effect because the emitted Line Of Sight (LOS).  


Wide bandwidth Width
 
(Band) FM located on the VHF (Very High Frequency) frequency spectrum where the available bandwidth that is wider than the AM broadcast band to the wavelength of the medium (MW = Medium Wave). Wide bandwidth on FM channels is also possible to load two channels, namely a data or audio. 



X . IIIIIII    Pattern Telecommunications System

Pattern telecommunication systems can be classified based on the direction of communication or direction information, the type of signal or dikomunikasian and authenticity of data signals are communicated. Electronic Telecommunications System patterns can be classified according to:  


Direction information, according to him the pattern of communication telecommunication systems can be divided into one-way and 2-way communication.
Type of transmitted signal, based on the type of data transmitted on the communication system Yag then communication can be divided into analog signals and digital signal communications.
Authenticity signal, based on the level of authenticity of the transmitted signal, the telecommunication system is divided into the baseband signal communication systems and telecommunications systems modulated signal.  


direction information
Simplex: One-way communication is a communication system with the information goes in only one direction. For example in radio and television broadcasts. Duplex: Two-way communication is communication with information system runs from two opposite directions Full duplex (FDX): Second place to communicate can send and receive information simultaneously. For example a telephone conversation Half Duplex (HDX): Second place to communicate, send and receive information in turn. For example in a conversation over the intercom.
Type Transmitted Signal Analog signals: Change in value (amplitude) signal takes place continuously. 


    

t  = time power 

Digital signal: Change the value of the signal (amplitude) takes place discretely.  


 

authenticity signals
Baseband Signal: Signal information is still showing the frequency spectrum of origin.
The voice signal on a phone conversation digital signal cable on the transmission of data between computers Signal Modulation Results: origin signal (baseband) superimposed on to a carrier signal having a frequency much higher. The process is called modulation, is used to remedy the lack of character signals with media
(Channels) are used.
Signals AM (Amplitude Modulation) signal for analog modulation PSK (Phase Sift Keying)
for digital modulation Directions  one-way information - two-way 2. Type  signal transmitted analog signals - digital signal  3. Authenticity signal baseband signal - modulated signal  


X  . IIIIIIII   Technology developments Wirememory flyer

Historical development of wirememory flyer include various types and specifications evolve. The first generation appear is a technology called Advanced Mobile Phone Service (AMPS). This technology is known as mobile services because of the configuration of antennae. Although AMPS shaped like a beehive, these cells can reduce energy consumption, improve access, reuse frequencies is limited bandwidth. However, this technology still has drawbacks because it does not anticipate the dynamic use of this technology in the market, so that consumers often get a busy signal.  

As the improvement of AMPS, then comes a new technology that is Multiple Access Technology, known as Frequency Division Multiple Access (FDMA). FDMA is a multiple access technique in which there is a specific frequency allocation. In FDMA frequencies used can be easily defined, but the use of these frequencies is not quite optimal. Consequently reappear new technologies that seek to cover the deficit, namely Time Division Multiple Access (TDMA) for the use of a greater frequency. TDMA utilizes specific frequencies that are divided into multiple users at once. Thus occurred the efficient use of existing frequencies. Channel sharing process among the users is done by the division of time slots to each user. This method is similar to the method contained on Time Division Multiplexing used in cable networks. The next-generation technology is a Mobile Switching Center (MSC). MSC is used in mobile telephone networks, where the MSC provides control systems for Mobile Base Station (MBS) and reconnect with the PSTN. MBS itself is a link between the mobile unit to the MSC. So MBS can be regarded as a transmitter which locate the nearest MSC to forward the received frequency of the mobile unit. MSC technology has landline same with Central Office (CO), except among users with network components wirememory flyer. Because its function is complicated, it is equipped with the MSC HLR (Home Location Register) as data storage and customer information stored permanently without depending on the customer's shoes. In the current era of 3G and 3.5G there, then in the future is expected there will be a new network technology called 4G. 4G is a technology that offers streaming video with high quality and data capacity is greater than the 3G. In addition, 4G also provide reception facilities Software Defined Radio (SDR), Orthogonal Freqiency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO), all of which use high-speed data transmission. However, there are shortcomings in 4G, which not everyone can take advantage of the technology because it is still limited and the pricing is expensive.  


 X  . IIIIIIII   Media Transmission Cable Type  

The transmission medium is the physical path that connects the transmitter and receiver. Through the medium of this transmission, the information signal transmitted by the transmitter is sent to the receiver at long distances. The transmission media can be wire media, such as coaxial, and fiber optic, or can also be wirememory flyer , for example by air. Characteristics and quality of the signal transmission of information, relying heavily on the characteristics and quality of the signal itself and also of the transmission medium used. 

I . Transmission Media Twisted Pair Twisted pair formed of two shielded twisted copper wire with a spiral pattern. A number of wire pairs are combined in one cable. Long strands of different can reduce crosstalk interference between wire pairs in adjacent cables.

 Pictures of Unshielded Twisted Pair (UTP) and Shielded Twisted Pair (STP)

    

Compared to coaxial and fiber optic, twisted pair is a type of what's most expensive and most widely used, both in analog and digital transmissions. The disadvantage is the limitation on the data rate and the range. This type of cable used in telephone networks or communication networks inside buildings. Characteristics of Twisted pair transmission media types can be described as follows: Utilization for analog signal amplifiers require every 5-6 km, sedangan for digital signal reinforcement is required every 2-3 km. Attenuation greatly influenced by the frequency, the higher the frequency is used the greater the damping. Susceptible to interference and noise. Interference can be reduced by using metallic woven as a protector. Twisted Pair Cables 2 types as shown in the image above, the UTP and STP. UTP is vulnerable to interference from outside, typically used for telephone wiring. STP less interference than UTP for use as a protective metallic webbing. This type provides better performance at high data rates, but also more expensive and more difficult to do than the UTP. UTP cables are divided into several categories. UTP category 3 usually has a length of strands of 7.5 to 10 cm. Transmission characteristics can reach 16 MHz, is used for the transmission of voice (voice) in an office building. Data rate can reach 16 Mbps within a limited distance. UTP category 4 have specifications characteristic of transmission up to 20 MHz. UTP category 5 has a tighter long strands, namely from 0.6 to 0.85 cm, to get better performance. Transmission characteristics up to 100 MHz, used for data transmission in the new gedung2. Data rate can reach 100 Mbps within a limited distance. UTP category 3 and 5 are typically used on a LAN (Local Area Network). 

II . Media Transmission Coaxial Cable Coaxial cable consists of two conductors. The inner conductor consists of a single copper wire, while the outer conductor form of woven metal. Both conductors separated by a dielectric material, while the outer layer be a sheath with a structure that can block the noise from the outside, and reduce interference and crosstalk. Compared with twisted pair cables, coaxial cables can operate on a wider frequency range with a longer range distance.

 Coaxial Cable Image

   


Utilization of coaxial cable is the most common on cable TV. This cable is also used on long-distance telephone network, and can carry 10,000 voice channels at once using Frequency Division Multiplexing (FDM). Currently, the coaxial cable is also used on an Ethernet LAN and backbone to the PSTN. Here are the transmission characteristics of this medium: Used for both analog and digital signals. Frequency and can support data rates higher than twisted pair cable. Performance is limited by the attenuation, thermal noise and intermodulation noise. For long distance transmission, the necessary amplifiers on every few km. The spectrum that can be used for signaling can be up to 500 MHz analog to digital transmission, the repeater is required every few km. 3. Media Transmission Fiber Optic Fiber optic is flexible and thin material, made from pure glass fibers, so although cable has a length of up to several hundred meters, light can still be transmitted from one end to the other. The glass fiber strands designed very subtle, its thickness is approximately equal to the thickness of a human hair. Glass fiber strands coated by two layers of plastic (2 layers of plastic coating) by coating the glass fiber with plastic, will get the equivalent of a mirror around the glass fiber. 


Image Fibre Optic Cable and Light Reflection Process In depth




From the picture above looks the part of a fiber optic, which is the deepest part (core) consists of one or more very thin fibers with a diameter of 8-100 lm. then the part that surrounds the core, called the cladding, made of plastic or glass layers with different optical properties of the core, serves to keep the light does not go out. The outer portion is a jacket that surrounds one or more cladding, made of plastics or other materials. This section keeping the cables from environmental conditions such as moisture, abrasion, and impact. Fiber optic cable has an advantage in terms of: the damping is very small, resistant to noise, bandwidth is very large, it is difficult for "tap" without damage it, no corrosion, more compact and lighter than the wire cable. The disadvantage is: can only be bent on a limited radius, beyond that, the light can not smpai at the other end, or even broken. Fiber optic cable is also very difficult to be connected, mechanical vibration can cause noise signal. Modern fiber optic cable can carry digital signals at a distance of approximately 60 miles (about 100 km). In the long-distance distribution lines there are usually additional equipment (equipment hut) every 40-60 miles, which serves the pick-up equipment that would accommodate, amplifies the signal, and then her retransmit-right signal to the subsequent equipment. 


X .  IIIIIIIII    loudspeaker  

 Loudspeaker, speaker or speaker system is a elektroacoustical transducer which converts electrical signals into sound vibrations form. Speaker is the last modifier machine or the inverse of the microphone. Speaker carry electrical signals and convert them back into physical vibrations to produce sound waves.  

Physical Form Loudspeaker  

   

Basic Loudspeaker 

In loudspeakers are diaphragm (also known as Conus) thin, somewhat stiff membrane is placed in the midst of a magnet. Magnet induces membrane to vibrate and generate sound. This membrane is also found on headphones. The loudspeaker converts electrical signals into sound vibrations that can be heard by humans. Briefly the most important part of the loudspeaker is: Konus, suspension, voice coil and magnet. Changes in the magnetic field inside the speakers will interact with a constant magnetic field which causes the coil moves as a reaction to the presence or absence of current. Conical part moves as a result of the voice coil so the air moves around the cone will form a pressure wave. This wave is heard as sound. Loudspeaker Loudspeaker resonance membrane type direct radiation should be highlighted so free to vibration. The elastic membrane protrusions, so it does not hinder the resonance frequency of the speaker membrane composition. The resonant frequency of membrane is free to distort the sound by responding to the vibration frequency of the signal strength approaching the original. Changes in the frequency response of the contents in terms of relative intensity noise harmony and timbre changes are not uniform. Because the membrane is not muffled, it is likely to produce a hangover with a ringing or resonance frequency around. If the frequency is within the scope of the bass, the bass will be boomy. 


Type Type Loudspeaker

Tweeter, is a type of loudspeaker made specifically for the reproduction of high-frequency sound (tone treble). loudspeaker of this type does not require rear resonance chamber.
Midrange, is a type of loudspeaker made specifically for the audio signal reproducing with medium tone (tone midle).
Woofer, is a type of loudspeaker made specifically to reproduce the audio signal with a low tone (bass tone). The loudspeaker of this type requires enough space resonangsi rear yan.
Fullrange, is a type of loudspeaker capable of reproducing audio signals on all the audio frequency range. Horn, is a type of loudspeaker made specifically to reproduce the audio signal in the frequency range of the human vocal.  


X .  IIIIIIIIII   Physical Magnitude (Stimulus) And Output Sensor  


Sensors or transducers are electronic components that can provide a change of electrical quantities output from the physical changes that it receives. Stimulus sensor is an entity or a physical quantity that can affect the sensor output. The sensor works by converting entities into electrical quantities. Seuatu sensor output will change if the sensor receives changes in the amount fifik (stimulus) to suit the type of sensor. Physical quantities (stimulus) that can affect the value of the output of the electronic sensor is as follows.  


Miscellaneous The Stimulus (Magnitude Physical)  
I . Sensor acoustic: wave (frequency amplitude, phase), velocity, spectrum, etc. 
II . Electrical: current, voltage, field, conductivity, permittivity, etc.  
III . The magnetic: field (amplitude, polarization, phase, spectrum) , flux, permenbility, etc.  
IIII . Optical: wave (amplitude, frequency, phase, spectrum), speed, reflection absorption  
IIIII . Thermic: temperature, rate of propagation of heat Mechanical: position, velocity, pressure, traction, density, velocity, altitude, thickness, mass, etc.   


      


The types of sensors used in automation systems based on the output signal produced can be divided into several types. Here are the types of sensors based on the output signal.  


Based Sensor Output Signal Type
 
I. Discrete sensor.
Discrete output voltage has a low voltage and high. Discrete sensors used to translate two contrasting conditions of physical phenomena into binary code.
II. Digital sensors.
Digital sensors have output data in binary form (digital) so it can be connected directly to the BUS system contained in the PLC. Digital Sensor has serial and parallel output.
III. Analog Sensor. Continuous analog sensor or sensors work by altering the physical phenomena into electrical quantities that can be measured, in the form of current, voltage. 


X . IIIIIIIIIII    Response time (Response Time) Sensor  


Assuming the time on the sensor indicates how fast response to input changes. For example, an instrument with a frequency response that is ugly is a mercury thermometer. The input and the output is the temperature mercury positions. Suppose the temperature changes occur gradually and continuously over time, as shown in figure (I) below.  


Sample response time (Response Time) A Temperature Sensor  


   



Frequency is the number of cycles in one second and is given in hertz (Hz). {1 hertz means one cycle per second, 1 kilohertz means 1000 cycles per second]. At low frequencies, which is when the temperature changes slowly, the thermometer will follow the change by "faithful". But when the temperature changes very quickly see figure (b) above, it is not expected to see a big change in a mercury thermometer, because he is slow and will only show average temperatures. There are various ways to express the frequency response of a sensor. For example "one millivolts at 500 hertz". Frequency response can also be expressed as "decibel (db)", which is to compare the output power at a particular frequency with output power at the reference frequency. Other conditions to consider in choosing the right sensor is to ask the following questions:Is quite meet the physical size sensor to be mounted in the necessary place?Is he accurate enough?Does he work on an appropriate range?Whether it will affect the quantity that is being measured? For example, if a large heat sensor dipped into the water a small amount of water, even cause the water heating effect, not the censor.Does he not easily damaged in use ?. Whether he can adjust to the environment?If the cost is too expensive?the right selection at the time of the expected life of the sensor to the application feedback space usage area? 


X . IIIIIIIIIII    Terms Sensor And Tranducer  

Sensor is a device used to detect symptoms or signals originating from a change of energy such as electric energy, physical energy, chemical energy, biological energy, mechanical energy and so on. example; Camera as vision sensors, as sensors hearing ear, the skin as a touch sensor, LDR (light dependent resistance) as a light sensor, and more.  


The sensor and transducer is a device or component that has an important role in a system of automatic settings. The accuracy and appropriateness in selecting a sensor will determine the performance of the system settings automatically. General Peryaratan Sensors and transducers In selecting equipment sensors and transducers are appropriate and in accordance with the system to be censored is necessary to note the general requirements of the following sensors: 1. Linearity Sensor / Tranducer There are many sensors generate output signals that vary continuously in response to input continuously changing. For example, a heat sensor can generate a voltage in accordance with the heat felt. In such cases, usually it is known exactly how changes in output compared with the input in the form of a graph. The following figure shows the relationship of two different heat sensors. The straight line in the figure (a). shows a linear response, whereas in figure (b). is a non-linear response. 



     


 II. Sensitivity Sensor / Tranducer sensitivity will show how far the sensitivity of the sensor to the measured quantity. Sensitivity is often also expressed with numbers that indicate the "change unit output than input change". Beberepa heat sensor may have a sensitivity that is expressed by "one volt per degree", which means a change of one degree in input will result in a change of one volt outputs. Other heat sensors may have sensitivity "two volts per degree", which means it has twice the sensitivity of the sensors first.The linearity of the sensor also affects the sensitivity of the sensor. If the linear response, the sensitivity will be the same for the whole measurement range. Paga image sensor with feedback (b) above will be more sensitive to high temperatures than at low temperatures.III. Response Time Sensor / Tranducer on the sensor response time indicates how fast response to input changes. For example, an instrument with a frequency response that is ugly is a mercury thermometer. The input and the output is the temperature mercury positions. Suppose the temperature changes occur gradually and continuously over time, as shown in figure (I) below. Frequency is the number of cycles in one second and is given in hertz (Hz). {1 hertz means one cycle per second, 1 kilohertz means 1000 cycles per second]. At low frequencies, which is when the temperature changes slowly, the thermometer will follow the change by "faithful". But when the temperature changes very quickly see figure (b) under then not expected to see a big change in a mercury thermometer, because he is slow and will only show average temperatures. 


 

There are various ways to express the frequency response of a sensor. For example "one millivolts at 500 hertz". Frequency response can also be expressed as "decibel (db)", which is to compare the output power at a particular frequency with output power at the reference frequency.  


X .  IIIIIIIIIIII       Tranducer / Sensor With Resistance Changes  


Tranducer are electronic components that may experience a change in the amount of electricity when responding to a change in the physical form of energy from the transducer component called. Tranducer in the world of electronics is often also referred to as a sensor. There are several types of transducer that will change resistance when responding to a change in the physical energy at the transducer or sensor. Tranducer which has the characteristics of resistance change of the LDR example, NTCdan PTC.  



LDR (Light Dependent Resistance) LDR is a resistor that can change the resistance value if the surface is exposed to light. Her condition is that if exposed to light resistance value is small, whereas if it is not exposed to light (dark conditions) then the resistance value is great. Images and symbols LDR  



   


NTC (Negative Temperature Coeffisient) is the NTC resistor resistance value can vary according to the temperature changes to it. If the temperature is higher then the resistance value is small, and vice versa, when the temperature, the lower the value the greater the resistance. Images and symbols NTC  



   

PTC (Positive Temperature Coeffisient) PTC is a resistor that the resistance value can vary according to the temperature against him. If the temperature is higher, the greater the resistance value whereas when the temperature is, the lower the resistance value is also getting smaller. Image and symbol PTC  


   




X . IIIIIIIIIIIII    POWER  AMPLIFIER 


   


  

POWER AMPLIFIER   OCL

Power Amplifier

Read more at: http://elektronika-dasar.web.id/power-amplifier/power-amplifier/
Copyright © Elektronika Dasar

Power Amplifier

Read more at: http://elektronika-dasar.web.id/power-amplifier/power-amplifier/
Copyright © Elektronika Dasar

POWER  AMPLIFIER  OTL 

 


POWER  AMPLIFIER  OT 






X  .  IIIIIIIIIIIIII    Regulatory System Tone (Tone Control) After Voltage Amplifiers  



Mechanical setting the tone on the audio system can be done before and after the voltage amplifier. Voltage amplifier is referred to in this section is not a power amplifier, but the amplifier audio signal to be processed to be given to the power amplifier. Articles Definitions and Working Principles Governing Tones (Tone Control) before the system is performed before setting the tone voltage amplifier. In a system of regulating the tone (tone control) that are installed after a voltage amplifier can be seen in the following figure. 



Regulator circuit image tone (Tone Control) Installed After Amplifiers  



  


The series regulator of tone in the image above is installed after the voltage amplifier circuit. At the time of maximum Treble tone regulator position, the input signal frequency transferred to the output capacitor C1 passes. At the time of maximum Bass sound regulatory position, the low input signal frequency is inhibited C2. The series regulator of tone were equipped with a regulator circuit loudness, High Filter and Low Filters which can be explained as follows: 

Regulatory Loudness circuit loudness mounted on volume control, loudness (depth) will have no effect on the position of more than half the volume setting, because the position of the setting the minimum volume signal is inhibited by the resistance of the potentiometer volume control.  


Figure circuit Loudness Manager

      


High regulator circuit Filter High Filter works if the switch is pressed, the position of the short-circuit capacitor C1. High frequency input signal is directly connected to the output.  
High Image Filter Regulator circuit  



  

Low Filter regulator low circuit filter works if the switch is pressed. In that position the capacitor C1 is connected a short, low frequency input signal is directly connected to the output.  


  




X  . IIIIIIIIIIIIIII   Tone Control Baxandall  

Tone control or regulatory baxandall 
baxandall tone is one type of active tone regulator on the audio system. Basically regulator of tone (tone control) serves to adjust the gain level of bass tones and treble tone level. Bass tones are audio signals at low frequencies and treble tone merupkan audio signals at high frequencies. Tone control baxandall an independent regulator circuit tone in setting the tone, the bass and treble tone settings do not affect each other. Examples baxandall tone control circuit can be seen in the following figure. 


   

Tone Control Baxandall

Read more at: http://elektronika-dasar.web.id/tone-control-baxandall/
Copyright © Elektronika DasarTone Control Baxandall 

Tone Control Baxandall    

 Baxandall tone regulator circuit above is an amplifier circuit with feedback network (feedback) and the active filter circuit. Where to strengthening the level of bass and treble tones separately and do not influence each other as follows. For bass tone, at the end of the low frequency audio (bass tones) where f <fB, the capacitor will be open circuit. Then the feedback effect consisting only of R1-R2. Op-amp will act sebgai inverting amplifier which will provide reinforcement / gain (AB) according to the following equation.  



     



Which means only depends on the setting potentiometer bass. limit the maximum setting potentiometer bass boost is the maximum (maximum bass reinforcement) and a minimum setting potentiometer bass limit is the maximum cut (maximum attenuation). At the time of the bass tone frequency increases, C1 will give effect to the R2 to C1 short so it no longer gives effect or response. Frequency fB where C1 will be effective at the maximum boost or cut the maximum is:   


    


So for frequencies above the frequency fB idak will be affected by the position potentiometer on maximum bass boos and cut or left flat. For treble tone, at the end of the high-frequency audio f> fT capacitor acts as short circuit. Then strengthening (gain, AT) will be governed by a potentiometer treble. In this condition potentiometer bass will not be effective because the C1 short (high audio frequencies) This happens when R4 >> R1 + R3 + 2R5 and strengthening the treble level (gain treble, AT) is.  


     




And treble frequency (fT) the treble tone control has a frequency response:    


      



X .  IIIIIIIIIIIIIIII    coupling Amplifiers   


Coupling in an amplifier circuit can be interpreted as a liaison between the amplifier and the next amplifier. Coupling the amplifier affects the frequency response of the amplifier, because the coupling will limit the frequency response in areas that can only be passed by the coupling. Coupling or link in an amplifier can be placed on the input, output and at the interface between the amplifier. Basically the coupling to the amplifier there are several types:   


Direct Coupling , Impendance, RC Coupling, Coupling Transformer Coupling Below is a description of some types of coupling to the amplifier as described above:  


Direct Coupling Direct coupling method is not used for connecting between the amplifier components. So with the direct method of coupling the first amplifier output directly connected to the amplifier input next. The following figure shows the use of the method of direct coupling.  



 

Amplifier circuits above the second amplifier level using direct coupling. Direct Coupling (Direct Coupling) give better frequency response, because the entire frequency response of the amplifier will first be given to the next amplifier directly and intact. This direct coupling method has a weakness in the delivery source voltage for the next amplifier should be higher and the adjustment of the amplifier output impedance between the first and subsequent amplifier input.  


Coupling RC  
RC coupling method using RC circuit configuration for connecting the amplifier output to the next amplifier input. The basic circuit RC coupling method can be seen in the following figure: 

   


In the above circuit RC coupling method shown by the configuration of R1, C1 and R2. R1 functions as a load for the first amplifier. C1 serves to hold the DC voltage from the first amplifier and to pass the AC signal from the first amplifier to the next amplifier. R2 serves as a determinant of the input impedance of the second amplifier. This configuration can isolate the DC bias voltage between the amplifier so as not to affect each other. RC coupling method is the solution of problems arising from direct coupling. RC coupling method also has its disadvantages in a limited frequency response in the low frequency response because there reactance (XC) is formulated as follows:  


  


From the formulation above shows the influence of the value of C versus frequency response can be passed, therefore the use of methods RC coupling is worth noting the determination of the value of C is used as reactance (XC) will affect the attenuation factor signal and the signal distortion when incorrect value.  

 

mpedance Coupling Coupling impedance is very similar to RC coupling. The difference is the use of an impedance device (coil) to replace the load resistor of the first stage. The basic circuit impedance coupling method can be seen in the following figure.  




The circuit above shows the coupling impedance circuit which was built with the RLC configuration L1, C1 and R1. L1 function sebgai first amplifier load, C1 serves to hold the first DC voltage amplifier and missed the first AC signal from the amplifier to the next amplifier. R1 serves as the input impedance of the second amplifier. L1 value should be high so as not to burden the first amplifier at low frequencies. impedance coupling configuration is not suitable for an audio amplifier, for audio amplifier work at low frequency. Function C1 and R1 together with C1 and R2 function on the RC coupling.   


Transformer Coupling transformer coupling method uses an trasformator as coupling or connecting the amplifier. Application of this coupling circuit with IF circuit contained in a receiver. Example amplifier with transformer coupling method can be seen in the following figure:

   



The main circuit coupling transformer is T1 that serves to connect the output of the first amplifier to the second amplifier input. Level of efficiency of use of transformer coupling method is very high because the bias voltage between separate amplifier and an amplifier impedance suitability good. The frequency response of the transformer coupling method is determined by the inductive reactance of the transformer itself 


X  .  IIIIIIIIIIIIIIIII     Power Amplifier Class AB  



Class AB Power Amplifier is made aiming to form a signal amplifier that is not defective (distortion) of the class A amplifier and power efficiency to get better as the class amplifier B. Because the class A amplifier has low power efficiency (± 25%) were due to the working point is at 1/2 VCC but it has the best signal quality. While the class B amplifier has excellent power efficiency (± 85%) for the working point approaches VCC, but the sound quality is not good. So that made class AB amplifier that has a power efficiency amplification (± 60%) with good quality audio signal. Class AB amplifier working point can be seen in the graph below the load line. 

 Point graph Working Class AB Amplifier  


   


By placing the working point class AB power amplifier circuit is between the working point of class A and class B as shown in the graph above the point of the circuit, the class AB amplifier is intended to get the basic characteristics of the composite amplifier amplifier class A and class B.  

 Basic series Power Amplifier Class AB  
  

Class AB power amplifier generally uses symmetric voltage source. The function of the diode in the class AB amplifier circuit above is to split the signal positive peak and the negative peak signal. Q1 and Q2 each side serves as a signal amplifier positive peaks and negative peaks. At the time of the sine then amplifies the signal in class AB amplifier circuit above can be calculated output voltage and power output of the circuit above as follows. RMS output voltage:  


    

Output Power:    
 
     

Where Vd is the diode voltage between the base and Vin circuit above is a basic circuit class AB power amplifier that is often applied to the power amplifier OCL, OTL and BTL. Class AB power amplifier is suitable for use as an audio signal amplifier because it has good power efficiency and the resulting output signal is not distorted.  



X  . IIIIIIIIIIIIIIIIII     Complementary Power Amplifier   


Power amplifier is another form of complementary push-pull amplifier that uses two PNP and NPN transistor that complement each other. Complementary amplifier gains are not necessary to the transformer input and output transformer. The basic circuit complementary symmetry power amplifier is as follows. 

 Complementary Basic series Power Amplifier  



 

Even without transformer for phase splitting the input power amplifier complementary, hence the presence of the transistors T1 and T2 are different in kind will by itself deliver (or die) alternately. At the time of the positive input signal cycle, then the base-emitter T1 gets forward biased so that the life T1 while T2 got the base-emitter reverse bias (for PNP) so T2 dead. The figure below shows the waveforms and the current direction at the time of the positive input cycle.  


Shape Wave At The Cycle Input Positive  


   


At the time of the input signal cycle turned into negative, then the base-emitter bias T1 gets back so that T1 death. While the base-emitter T2 gets forward biased (for PNP) so that T2 becomes alive. The figure below shows the waveforms and the current direction at the time of the cycle of negative input. 

Wave Forms In Negative Input Current Cycle  




  

At the time of the input signal cycle collector current ic positive direction from right to left, and when the input signal cycle collector current ic negative direction from left to right. This indicates that the polarity of the output signal in accordance with the polarity of the input signal. The basic configuration of each amplifier transistor in complementary symmetry power amplifier is an emitter follower, because the output signal is taken from the foot of the emitter. Thus the voltage gain Av of the amplifier is less than one, or not corroborated. While phase input and output signals are the same or opposite.  



X  .  IIIIIIIIIIIIIIIIIII   STK 4036 Power Amplifier IC - STK 4044   


 A series of power amplifiers using IC STK has more than enough power for the purposes of an audio amplifier in the home. Power amplifier IC STK is often used as well in the audio amplifier music devices such as keyboard and Orgel. The sound quality of the power amplifier using IC power STK has a high fidelity audio frequency response in every good range so that it can reproduce the sound with bass and treble tone nicely. Power amplifier IC STK is an IC designed specifically by Sanyo-purpose audio amplifier with medium power. In a series of power amplifier IC STK4036 - STK4044 below is a circuit that can be used to type IC STK 4036 until 4044. STK STK power amplifier output power using this circuit is in accordance with the type of IC STK used. For 8 Ohm speaker load circuit power amplifier output power is 50 watts 100 watts depending samapai IC STK used. Complete range can be seen in the following figure.  


The series Power Amplifier IC STK 4036 - STK 4044  



     

Daftar Komponen Rangkaian Power Amplifier IC STK 4036 – STK 4044 R1-4 = 1Kohm, R10 = 10Kohm, R2 = 33Kohm, R11 = 680ohm, R3-8 = 100ohm, R5 = 0.22ohm/5W, R6 = 10ohm/2W, R7 = 6,8ohm/2W, R9 =12Kohm C8 = 100nF, C11 = 1nF, C1=560, C13 = 100uF/25V, C2-7 = 1uF/63V, C14= 10pF, C3-12 = 220uF/63V, C4-5-10 = 100pF, C6-9 = 47uF/63V L1 = 15 Lilit pada R6 email 1mm F1-2 = 2A IC1 = STK4036……STK4044

Read more at: http://elektronika-dasar.web.id/power-amplifier-ic-stk-4036-stk-4044/
Copyright © Elektronika Dasar

List of circuit components STK 4036 Power Amplifier IC - STK 4044 R1-4 = 1Kohm, R10 = 10kOhm, R2 = 33Kohm, R11 = 680ohm, R3-8 = 100ohm, R5 = 0.22ohm / 5W, R6 = 10ohm / 2W, R7 = 6,8ohm / 2W, R9 = 12Kohm 100nF = C8, C11 = 1nF, C1 = 560, C13 = 100uF / 25V, C2-7 = 1uF / 63V, C14 = 10pF, C3-12 = 220uF / 63V, C4-5 -10 = 100pF, C6-9 = 47uF / 63V L1 = 15 Lilit on email R6 1mm F1-2 = 2A IC1 = STK4036 STK4044 ......  



Power supply to the power amplifier circuit STK4044 STK 4036 until this use symmetrical power supply with output voltage corresponding to the above table. Output power provided by the power amplifier depends on the power amplifier IC STK is used, where the power output of each IC STK 4036 - STK4044 can be seen in Table Characteristics Power Amplifier IC STK 4036 - 4044 STK above. 



X  .  IIIIIIIIIIIIIIIIIIII     Variable Symmetric Power Supply 10A    



Power supply variable and symmetric is a necessity in a space experiment. This series of power supply to the circuit under variable symmetry is one of the power supply circuit that can be used. Symmetrical variable power supply circuit is capable of providing a variable output voltage of 1.2 volts DC to 30 volts DC with a maximum current of 10A per output lines. This symmetrical power supply circuit using a variable voltage regulator circuit LM317 and LM337 with a current amplifier in the form of transistor TIP147 and TIP142. The circuit is suitable for use in space experiments because it has a symmetrical output voltage and adjustable voltage level and has a drain current capability of 10A. The full range of variable symmetric 10A power supply can be seen in the following series of images.  


Variable Symmetric circuit 10A Power Supply

      

Symmetrical variable power supply circuit is divided into 3 main full-wave rectifier circuit, voltage regulator circuit of positive and negative regulators. From the voltage regulator positive and negative voltage regulator is as follows. The hand wave circuit (Rectifier) ​​Part of this wave rectifier provides a DC voltage output ± 32 volt DC symmetrical to the ground. It was built with stepdown transformer 32 volt CT on the secondary, full wave rectifier diode bridge and filter using a capacitor 10000 uF / 40V. Positive Voltage Regulator circuit variable positive voltage regulator section of this variable is used to set the output voltage to be controlled positive track level and able to provide a maximum current of 10A. Variable positive voltage regulator circuit using LM317 variable voltage regulator IC as a controller output level. Then the positive voltage regulator is regulated by a 2.2 Kohm potentiometer as a control reference voltage regulator LM317. As a current amplifier using TIP147 PNP transistor which set common base so that the output voltage will follow the control by IC LM317 voltage and maximum current carrying capacity following the maximum capability of the transistor drain current (10A).   


Negative Voltage Regulator circuit Variables As part of the positive regulator, part of this negative voltage regulator circuit arrangement is similar, only the components used are different. Negative voltage regulator using LM337 negative voltage regulator IC, amplifier current using TIP142 NPN transistor with a current carrying capacity of 10A maksismum. Negative output voltage controller using a potentiometer track 2.2 Kohm as giving a reference voltage regulator IC LM337 negative voltage. Symmetrical variable power supply circuit 10A has the capability of state short circuit protection (short circuit), and excess heat (over heating) as the voltage regulator IC LM317 and LM337 IC used in power supply circuit symmetrical variables.  



X  .  IIIIIIIIIIIIIIIIIIIII   Car Audio Head Unit   


Panasonic head unit production is a combination of radio, CD and MP3. Audio equipment is very common is a radio / tape player / CD player / DVD player that is generally described as a Head unit, also called head deck.  

Now it has developed technology added CD player head unit with MP3, Ogg WMA, AAC and USB support, Bluetooth and Wi-Fi. Most modern cars have a CD player and some CDs cahnger has the option, which can be mounted double disc also in the head unit itself or placed in a separate console. 


Examples Head Unit In Car Audio Systems  


  


Last even has added a DVD player and LCD screen. The LCD display is also integrated into the console onstrumen. DVD head unit feeding the video output to prop installed separately or placed into the backrest to see passengers in the rear. The video screen can also show video output of other components such as navigation systems, game consoles or a parking camera that can be automatically activated when the car is moving backwards. Head units generally offer some cross-over (audio cross-over) and equalization. Generally include parametric or graphic equalizer. Cross over undercooling filters typically use high frequency and low frequency only transmit a certain frequency range to a specific component. Subsonic filter are not generally handle amplifier head unit  



    




X  .  IIIIIIIIIIIIIIIIIIIIII    Ultrasonic transducer   



Ultrasonic transducers are electronic components that can convert electrical energy into mechanical energy in the form of ultrasonic sound waves and vice versa. Ultrasonic sound waves are sound waves that can not be heard by humans normally because the frequencies above 20kHz ultrasonic waves. Ultrasonic transducer in the application are always in pairs, ie there ultrasonic transducer that serves as a transmitter (transmitter) and the ultrasonic transducer as a receiver (receiver). In general the ultrasonic transducer on the market is a pair and can be seen in figure one ultrasonic transducer following examples.  



Sample Forms Ultrasonic Transducer   

    


Ultrasonic Transducer Construction  


  

Construction ultrasonic transducer consists of main parts of the active element, and wear plate (metal plate). The active element of the ultrasonic transducer is piezoelectric which serves to convert electrical energy into mechanical energy in the form of ultrasonic sound waves. Piezoelectric ultrasonic transducer used in generally made of ceramic, but for applications or special needs that require high performance piezoelectric element in the ultrasonic transducer is made of a polymer or composite materials. In some piezoelectric transducer element is also added in addition to backing which serves to control or reduce vibration frequency of the ultrasonic piezoelectric active element that does not penetrate to the back of the transducer, so that the ultrasonic energy emitted just ahead alone. Wear plate (metal plate) in the ultrasonic transducer serves to protect the piezoelectric element when the transducer works. Wear this plate should be able to work on a vibration with high frequency (ultrasonic frequency) and resistant to corrosion, because the ultrasonic transducer is often used on the device without the protective (sensor in the open position). In the application there are a few things to note from an ultrasonic transducer.  


Characteristics of Sound Pressure  


  


Characteristics of sound pressure (Sound Pressure Level; SPL) on the use of ultrasonic transducer which indicates the volume and power of ultrasonic sound generated transducer. Mathematically sound pressure (Sound Pressure Level; SPL) can be formulated as follows  


 

Where "P" is the sound pressure (Pa) and "Po" is reference sound power (20μPa). 


Receive Sensitivity Ultrasonic Transducer  


   


Reception sensitivity of ultrasonic waves from the transducer will influence the performance of the use of ultrasonic sensors. This ultrasonic transducer sensitivity can be expressed in the following mathematical equation.  






   

Where "S" is the sensor voltage (V) and "So" is the sound of a reference voltage (V / Pa)  


Ultrasonic Wave Beam Radiation What is meant by radiation beam is the angle beam of ultrasonic waves generated ultrasonic transducer. It is worth noting because it will affect the quality of their reception and emission of ultrasonic transducer. There are several ultrasonic transducer equipped horn to focus the beam of ultrasonic waves, so the wave emission performasi Utrasonic of transducer optimized.  



X  .  IIIIIIIIIIIIIIIIIIIIIII     Digital Signature Transponder   


Digital Signature Transponder is devais crypto system uses questions and answers. It is a second generation of RFID tag is specially used for security systems, where only a key can access the security system. This system can be applied for example in car security systems. At the time of initialization, security systems and transponder exchanging secret encryption key. This key can not be read, only the transponder response to a question posed a security system that can be read.  



  


Transponder is devais complex logic and systems are designed to operate at very low power. Image of the transponder can be seen in the image above. In its application, the security system sends a random number of bits (question) to the transponder using Pulse Width Modulation. On the question transponder entered into a register of questions. For a short time, the energy provided by the system of security and encryption logic circuit will produce a response (signature). In figure 2 can be seen Crypto Transponder system.  

 Crypto Transponder System   



    


The response R is a function of the encryption key Ke, challenge RAND, and cryptographic algorithms Fc. 


 

The response is returned to the security system by using Frequency Shift Keying (FSK). The security system calculates the expected response using the same algorithm and the same encryption key and compares the responses received from the transponder with the calculation results. The results of calculations of the expected response can be completed simultaneously with the communication between the transponder with a security system, or after receiving a response from the transponder. If the result is the same, then the information will be sent to the management computer. The advantages of this system are as follows: The response is different at each time, depending on the question (challenge). The result is a dynamic authentication process. No part of the encryption key that is sent after initialization. The encryption key can not be read. Transponders can not be duplicated. The encryption key can be locked or changed if desired by re-initialisation.    


 X  .  IIIIIIIIIIIIIIIIIIIIIIII     With Security System Identification and Authentication   


Information security has the function to protect business information from theft, replacement, and destruction by parties who have no right of access to such information. It is necessary for user identification capabilities by information security systems, to prevent access to information by unauthorized users.  


   


Identify the terms of the security system, the result of the authentication protocol is one of the receipt of the identity of a party that is known, or the denial of identity is not known. More specifically, the purpose of the identification protocol is:  


If A successfully authenticate identity to B, then B will continue the protocol after receiving the identity of A. transferability: B can not use exchange identification with A, to be able to do imitations of A to third parties C. Impersonation: Very little likelihood of the different C A, do identikasi protocol with B and take on the role of A, which can cause B to accept it as the identity of A. Tranferability and Impersonation applies to the number of authentication process very much.  



In the Cryptographic Issues Identification From the standpoint of cryptography, the problem of identifying includes two important tasks, namely, the identification and authentication of the identity of conduct. Some types of cryptography that can be used for identification systems include: Knowledge identification system based on the knowledge of a secret, such as a password or PIN (Personal Identification Number) to demonstrate the validity of identity. For some applications with high security, are not implemented with this system, because the security level is not too good. Biometric identification systems based on biological attributes, such as fingerprints, voice, retina, or face recognition. With either of these attributes, the identity of a person can do. Owners Identification by virtue of the ownership of an object. This method is common and is still used widely in the future. It can be implemented with a proprietary magnetic card, smart card, and others. For the following discussion will use the term key to things that are used for identification system above. All cryptographic system described above is a static authentication procedure. Static authentication means the security system can recognize the identity of the key, but the key can not do an introduction to the security system. Mutual authentication procedure that allows the key to ensure the identity of the security system is one of the features that can increase the security level of a security system. With this procedure, the secret known only to the key and the appropriate security system will not be issued by the lock to the other systems. A higher level of security can be obtained with a symmetric algorithm known as protocol questions and answers (challenge / response protocol). The security system will ensure the identity of the key by sending a query (challenge) and then will check the answer (response) of the key. The correct answer will be given by key only if a secret known by the security and lock system. This concept has several advantages, namely: in normal use, the secret is not interchangeable, and the questions and answers can vary from time to time. Identification With Password or PIN password Password involve conventional time-invariant (unchanged by time). The basic idea is a password that is associated to a user consists of a sentence consisting of 6 to 10 or more characters. It is a secret that is known by the user and the system. PIN (Personal Identification Number) also belong to the category of the password time-invariant. PIN is usually used in conjunction with ownership of an object (token) eg smart card. This will provide a level of security that is better because other people can not gain access without knowing the PIN when the token is lost or stolen. Generally kept short PIN between 4 to 8 digits. To prevent random searches PIN (because the number of possible bit), it would require additional mechanisms, such as locking the card at ATMs to mistake entering your PIN three times in a row. Since man is hard to remember the secret code that is long enough to get a high enough level of security, the password and PIN can not be made long so the authentication security system is not strong enough. Authentication With Question And Response The idea of ​​cryptographic protocols with the question and the response is an entity that will demonstrate the validity of their credentials to another entity (the security system) to demonstrate the secrets himself to the security system, without opening the secret to the security system, when the protocol is in progress. This can be done by providing a response to the question of time-variant (changes with time), in which the response depends on the entity secrets and questions provided. Questions are generally in the form of a number of entities selected one at random and secret. Although the communication lines are tapped by the time the protocol takes place, the response of an identification process would not provide useful information for further identification. Time-invariant parameters can be used in the identification protocol to prevent recurrence. This parameter is generally referred to as a unique number or nonce. Nonce value that is used no more than once, for the same use. This is done to prevent a repetition that can be detected. Random numbers can be used in response to a question mechanism, to provide uniqueness and prevent recurrence. Random numbers also provide a system that can not be predicted. The term random number, which is used in the context of the identification and authentication protocols, involving pseudorandom numbers that are not predictable. Pseudorandom number is a number that seems random, but in fact there is recurrence with iteration very long period.  




X  .  IIIIIIIIIIIIIIIIIIIIIIIII     Angular Speed Sensors Gyroscope ADXRS150  



Sensor gyroscope is the angular velocity sensor is used to measure the rotational speed of an object. Gyroscope sensor module can be found in the IMU (Inertial Measurement Unit) is a unit in an electronic module which collects data angular velocity and linear acceleration are then sent to the CPU (Central Processing Unit) to get the data the presence and movement of an object.  


In general the results of measurements of the angular velocity of an object using a gyroscope sensor on the horizontal axis can be expressed by the following equation.  


  

From the equation above, can be obtained actual angular velocity is expressed by the following equation: 


     


Gyroscope output signal rm (t) generally contain angular velocity signal r (t), random noise w (t), and the bias b (t). ADXRS150 gyroscope from Analog Device, an electric gyroscope which has a scale of 150 ° / s. ADXRS150 gyroscope shown in the following figure   


Angular Speed Sensors Gyroscope ADXRS150    


    



ADXRS150 is the input voltage to a DC voltage of 5 volts, while the output voltage between 0.25 volts to 4.75 volts. When at rest, ADXRS150 gyroscope sensor has a voltage offset amount equal to half of the input voltage or about 2.5 volts. ADXRS150 gyroscope is used to measure angular velocity or how fast an object is rotating. ADXRS150 gyroscope will issue a voltage whose value is proportional to the angular velocity, the value is determined by the value of its sensitivity. The sensitivity value has units of millivolts per degrees per second (mV / ° / s). ADXRS150 gyroscope has a sensitivity value of 12.5 mV / ° / s.  




X  .  IIIIIIIIIIIIIIIIIIIIIIIIII       Pressure Sensor With LVDT   



There are several types of pressure sensors, one of which is an LVDT (Linear Variable Differential Transformer). LVDT (Linear Variable Differential Transformer) is a pressure sensor that is read through shifting magnetic core. LVDT (Linear Variable Differential Transformer) is having a differential transformer working principle is based on the principle of variable inductance. An LVDT is illustrated in the following figure, consists of three pieces of the coil windings are symmetrical on an insulated coil.  

 Construction LVDT (Linear Variable Differential Transformer)

    


LVDT (Linear Variable Differential Transformer) consist of a primary coil and two secondary coils are identical, the coils are spaced axially and rolled in the framework of a cylindrical coil, rod-shaped magnetic core and placed in the middle of the coil arrangement and can move. The movement of the LVDT core magnet will produce a magnetic inductance voltage value (GGL induction) at the output of the secondary coil 1 and 2. From the working principle of a differential transformer LVDT (Linear Variable Differential Transformer) tersbut can then be made using the pressure sensor LVDT is illustrated as shown below , 



Illustration picture Pressure Sensor Using LVDT  


  

The change in pressure inside the bag will result in a change in the position of the magnetic core LVDT coils, resulting in changes in magnetic induction in the secondary coil 1 and 2. With the change in the magnetic induction in the secondary coil 1 and 2 are then output coils 1 and 2 will produce a voltage magnitude of the magnetic induction perseseran comparable magnetic core LVDT due to pressure changes in the sac. Shifting magnetic core (bar magnets) in the middle of the coil will cause the output voltage to the coil that gets the induction of the magnetic core.  




X  .  IIIIIIIIIIIIIIIIIIIIIIIIII     video amplifier circuit



  



       

picture  : Two Transistor transconductance circuit Modulator (T3M)

modulator Images
For broadcast TV, the image signal is transmitted using modulation AM. For that you need to know in advance about how to make waves modulated AM. One of the most common ways is to utilize the transconductance of the transistor. In a transistor amplifier voltage magnitude of the voltage gain factor is:
Av = - gm. ZL
Av = voltage gain factorTransconductance gm =ZL = load impedance amplifier output
The value of the transconductance (gm) is directly proportional to the bias current in the collector (Ic), and transconductance (gm) is also influenced by the temperature at which at room temperature (300 ° K) value gm = Ic / 0026, so the equation amplifier voltage in above could be changed to:
Av = (Ic / 0026). ZL
From this equation shows that the voltage amplification factor is directly proportional to the bias current flowing in the collector (Ic). Thus if in some way we can change this Ic then the voltage gain factor will vary linearly to changes in the Ic. When this reinforcement means changing the voltage or amplitude of the output signal generated will change as well. Well this is where the AM modulated signal is then generated.
Now we see how the amplifier circuit currents. As the name implies, Stronger currents do not amplify voltage amplitude, but amplify the current. So when we enter into the amplifier input signal then the voltage at the output currents will be equal to the voltage at the input, while the output current flowing in the enlarged.
Furthermore, voltage amplifier and amplifier currents that we assemble in series so that we will get AM modulator circuit that is very popular so-called Two Transistor transconductance Modulator (T3M). The circuit is considered very suitable for use as a modulator of images for:
1. The result of highly linear modulation2. Capable modulated by a video signal that has a very wide bandwidth3. Able to produce the modulation index is high (over 90%).4. RF power output is generated relatively large5. The circuit is simple / complex6. Components are easy to obtain and relatively cheap
T3M is a two-transistor amplifier circuits that are arranged in series as shown in Figure (1). The first transistor (TR1) is a voltage amplifier with input in the form of a carrier signal (Vc), while the second transistor (TR2) is a flow amplifier with input in the form of a video signal (Vm). Broadly speaking rangkain workings are as follows .:  


TR1 magnitude amplification factor depending on the current flowing in the bias current in the collector (IC1) wherein the magnitude of this IC1 would roughly equal to the current flowing in the emitter (IE1), assuming the current that flows in Base is very small so that it can be ignored. Likewise, the amount of IE1 will be approximately equal to IE2, the current flowing in the emitter of TR2, given TR1 and TR2 is coupled in series. IE2 The amount is equal to the voltage divided by resitor R4 VE2. And since R4 precious remains, it will be comparable with the VE2 IE2.
Well since TR2 is a current amplifier (not the voltage amplifier) ​​then VE2 will always be proportional to the input signal (Vm). So the amplification factor TR1 will be proportional to the input signals are fed to TR2, namely Vm. TR1 is then given input signal amplitude carrier remains fixed, the output of TR1 (Vo) will be the AM signal where the amplitude varies in proportion to the signal Vm.
Pictures (2) is an example of a series of T3M where TR1 given input signal carrier [Vc (t)] while the TR2 given video signal input of the polarization that has been reversed [Vm (t)]. From the series is then generated image signal bermudulasi AM [Vo (t)]. In the picture (2) looks a clamping circuit befungsi restore the DC component of the video signal due to coupling capacitors.  


 


picture  : One example of the image modulator circuit 


Modulation index (expressed as a percentage) is a number that tells you how big the carrier signal deviates result of signal modulation. Modulation index of 100% means the entire modulated carrier signal total, and this should be avoided. According to the standards in force, the maximum modulation index for the image signal is 90%. This figure will be achieved when the video signal is at white peak (peak white) or the brightest image.
When the modulation index exceeds 90% will cause incidental Carrier Phase Modulation (ICPM) at the receiver. The effect is a form of noise is very annoying when the picture on the screen there are very light or white tops. For the modulation index should be limited so as not to exceed 90%. The series of "White Clip" is usually installed to limit this modulation index.
Modulation signal is put into this circuit is a video signal, then the magnitude of the modulation index can be set by adjusting the magnitude of the input video level. In the example in Figure (3) the magnitude of the modulation index is regulated through variable 100 ohm resistor located at the amplifier input video. Pictures (3) is an example of an image modulator circuit complete with pictures oscillator carrier signal (33.9 MHz), a video amplifier and inverting phase, clamping circuit and modulator AM.  



 


Picture   :  An example of an image modulator circuit  




Aircraft Parts Television Receivers   


Information Sheets There are two types of television receiver that is black and white television and color television that is compatible. Compatibility can be achieved because of the color television signal receiver divided into two kinds of luminance signal containing the image detail synonymous with the video signal receivers black and white television. In order for a color television receiver can occupy the same channel width used in the television receiver is not all black and white, the primary colors emitted but only two color difference signals. The revival of primary colors carried on the television receiver at the chrominance demodulation. 1. Raw Colour TV System In America and Japan, color television transmitters using the NTSC standard system. On the NTSC standard system also has the same compatibility as the PAL system. That is going to come anyway a good image when color TV transmitter program captured by the television receiver putih.Sistem black color TV standard NTSC PAL system is almost the same as the difference lies in the method of making a sub carrier signal color, the number of scanning lines, vertical turn ent frequency. The system used is usually the PAL system. Differences system both can be seen in Figure 1 below.  


    

Block Diagram System NTSC Colour TV Receiver   




    


Receiver System Block Diagram Figure Color television PAL 2.
Receiver Block Diagram Colour TV color TV signals can be divided into three groups namely the luminance signal (same as the video signal for black and white television receiver), signal synchronization and chrominance signals (color sub-carrier) The difference receivers black and white television and color secarablok diagram can be seen in Figure 3 below.  



     

TV Receiver Block Diagram Figure Black and White
From the figure it can be seen that the difference between the two adalahadanya range of color reproduction on a color TV receiver. Color TV picture receiver mechanism works as follows. The image signal comes to it from passing tuner IF amplifier, video detector, amplifier circuit matrix video and finally to the picture tube. Synchronization signal and chrominance signals are separated on the first level of the video amplifier, and respectively to the synchronization circuit and a series of color regeneration. While voice signals are separated in the IF amplifier and finally mencapaipenguat sound image. Here is an example block diagram of black and white television and its waveform  


   



Pictured above Colour TV Receiver Block Diagram 4. Each Function Block Diagrama. Tuner order acceptance can be obtained coverage telecast used konver system consisting of an RF amplifier, mixer and local oscillator. Duty mixer mixes high-frequency input signal is successfully passed by the circuit Tunner with local oscillator output signal in order to obtain wave TV intermediate frequency (IF). So by using a converter (converter) high frequency signal from the tuner (tuner) is converted into an intermediate frequency IF.   



   


Pictured above Tuner circuit b. Figure IF amplifier output signal from the converter then dipoerkuat sehinggadiperoleh gains large enough for TV receivers. IF amplifier pictures have a gain of about 100 times. IFgambar amplifier section is connected to the feedback circuit AGC (Automaticgain Control / regulator automatic gain) as well as given in the HF amplifier in the circuit tuning the aim is that the output voltage at the IF amplifier is always constant although teganganinputnya fickle. c. Video detectors composite video signal from the video IF amplifier detected in the video detector. What is meant by a composite video signal is a video signal that still contain synchronization signals, blangking. Video detectors typically use a diode because it has properties of good linearity and distortion is also small. Download the video signal in the negative or positive depending on the level of the amplifier rangakain image after level luminance signal detector that is important to the cathode picture tube should always negative polarity. d. Video amplifier video amplifier serves to strengthen the luminance signal berasaldari video detector in order to have enough strength untukmenggerakkan picture tube. From this series of chrominance signals sinkronisasidan signal is issued and each diberikankepada berikutnya.Agar process can produce good color image on the picture tube, the luminance signal from the detector is amplified by the video amplifier video about a hundred times and delayed 1 s by the delay circuit. e. When the AGC circuit TV wave power fickle and that signals are fed to the video detector constant then the HF amplifier and IF amplifier should be set automatically by the circuit AGC.Bila received wave power amplifier HF strengthening weak then made the maximum and just strengthening IFyang amplifier is set by the AGC circuit. When the TV wave power received is greater than a certain price, the strengthening of HF is also governed by the AGC circuit. f. The deflection circuit Synchronization deflection synchronization circuit can be divided into four parts: the synchronization circuit, a vertical deflection circuit, the horizontal deflection circuit and the high voltage generator circuit. g. The series Sync synchronization signal circuit is separated from the composite video signal and then amplified. Horizontal synchronization signal is separated from the vertical sync signal by using a frequency dividing circuit. h. It consists of a series of vertical deflection sawtooth wave generator circuit, amplifier circuit and the output circuit. Sawtooth wave generator circuit is synchronized with the vertical sync signal and generate a sawtooth wave 50 Hz. Inikemudian signal amplified to gain power so that the vertical deflection coil is able to distort the electron beam on the tube in the vertical direction. i. Horizontal deflection circuit In this section shaped electric current sawtooth frekuensi15625 Hz supplied to the horizontal deflection coils in order to distort the electron beam tube horizontal direction. j. The series of High Voltage Generator In this section generate high voltages to supply the high voltage on the picture tube anode. Horizontal flyback pulses of horizontal deflection in the circuit is an enlarged USING flyback transformer. Enlarged pulse is then rectified using rectifier pendobel and resulting high output voltage direction. k. By using the color signal demodulator demodulator color signals in demodulasikan color difference signal U and V. In this demodulation system third color difference signals demodulated signals directly from the color sub-carrier. This means that of the two signals; color difference (B-Y) and (R-Y) initially generated by demodulates each signal from the signal sub carrier color U and V, kemudiansinyal (G-Y) is produced by combining the two sinyalperbedaan color (signal B-Y and R-Y). For more details, described as follows:  


   

The matrix demodulation circuit UV and l. Third Color Output Signal circuit color difference signals coming from demodulation of color and luminance signals coming from the video amplifier are mixed so as to produce three primary colors red, green and blue. These three primary colors is strengthened so that the amplitude of the voltage is enough to drive a color picture tubes. The drive system is called "primary colors propulsion methods" for color picture tubes is driven by three primary colors. In the "color difference signal propulsion methods" color picture tubes driven by three color difference signals and three for the luminance signal is passed through the electrodes different then combined into the three primary colors of R, G and B in the picture tube. m. Differences Work Frequency Receiver System PAL television NTSCdan differences PAL and NTSC system hardware can be seen in Figure 1 and Figure 2. In addition, there are differences in the working frequency, the difference can be seen in Table 1 dantabel 2 below. Table 1. Frequency Channel
No. NTSC channels (MHz) PAL (MHZ) Channel 1 Channel 2 Telecomm 47-54Kanal 3 60-66 54-60 54-61 66-72 61-68 Channel 4 Channel 5 Channel 6 76-82 174-181 82-88181 -188Kanal 7174-180 188-195Kanal 8180-186 195-202Kanal 9186-192 202-209Kanal 10192-198 209-216Kanal 11198-204 216-223Kanal 12204-210 223-230Kanal 13 210-216UHF 470- 890590-770 Table 2. another difference NTSC PAL Description freq Pembelok V 60 Hz 50 HzJml grs 625Frek Pembelok H H 525 15 750 15 625 Hz HzLebar 6 MHz channels 7 MHzVHF 54-214 47-230 MHzUHF 470-890 MHz 590 MHz - 770 color MHzFrekuensi 3.58 MHz 4.43 MHz  


Synchronization is the process of setting the course of several processes at the same time.

The main objective is to avoid inconsistencies synchronization of data for access by several different processes (mutual exclusion) as well as to set the sequence running processes so that it can run smoothly and avoid deadlock or starvation.

Synchronization is generally done with the aid of a synchronization device. In this chapter, we discuss some synchronization devices, namely: TestAndSet (), Semaphore and Monitor.    



X  .  IIIIIIIIIIIIIIIIIIIIIIIIIII     VIDEO SWITCHING CIRCUIT

 
Installing cameras everywhere become viable is now, thanks to the drop in the price of a security camera. However, providing a dedicated monitor for each camera attached inefficient. In addition, CRT monitors may suffer from phosphor burn if used to display static images from a single camera. Circuit video switcher is required to show more than one view in the monitor. Take a look below the circuit schematic:  


   


 



     

MAX454 is the core of this video. This is a video multiplexer amplifier assembled by Maxim Semiconductor. Pay attention when designing the video signal path around this chip. Track ground plane can be inserted between video signal channels to prevent crosstalk and noise interference. Chip directly be soldered to the PCB. A sequencer CD4017 encouraging indicator channel (LED1-LED4) can be seen here. This output will decode the binary data bits 2 by D1 .. D4 to MAX454 multiplexer address. The output of the sequencer is also the drive indicator.  

Digital Signature Transponder

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imum Power Supply Typical Power Supply Power into 8R THD for Power max. 50 W ± V ± V W 20 HZ-20 KHZ into 8R Load Gain=28db Gain=40 db STK 4036 15 ±53,5V ±35V 50 0.003% 0.008% STK 4038 ±58V ±40V 60 0.003% 0.008% STK 4040 ±63V ±43V 70 0.003% 0.008% STK 4042 ±67V ±46V 80 0.003% 0.008% STK 4044 ±74V ±51V 100 0.003% 0.008%

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Copyright © Elektronika DasarPower supply to the power amplifier circuit STK4044 STK 4036 until this use symmetrical power supply with output voltage corresponding to the above table. Output power provided by the power amplifier depends on the power amplifier IC STK is used, where the power output of each IC STK 4036 - STK4044 can be seen in Table Characteristics Power Amplifier IC STK 4036 - 4044 STK above.