Showing posts with label amplifier. Show all posts
Showing posts with label amplifier. Show all posts
Monday, November 17, 2014
5000W High Power Audio Amplifier
The High Power Amplifier has great advantages are 5000W ultra-light, high-power audio amplifier, without switching-mode power supply. This ambit is of an 2 x 2,500W RMS Stereo amplifier, super-light and after switching-mode ability supply. The ambit aloof shows a channel, and the ability accumulation that it assists to the two channels. The audio ambit should be duplicated, but the ability accumulation assists to the two channels after problems.
| Click To view larger | 5000W High Power Amplifier Audio Circuits Diagrams |
A adapted affliction should be destined to the careful agent of the audio line, that should be of audio-high-quality, of the blazon acclimated in microphone pre amps ascribe line. The accomplished accumulation (2 channels) of 5,000W RMS it should not counterbalance added than 32 lbs, already central of an adapted brownish box.
WARNING:
This ambit is alone for abecedarian use. It contains not-isolated genitalia of the electric AC net and it can be actual dangerous. The access for the speakers are not abandoned of the calm AC net and it requests added care. This action seeks to acting a accepted ability accumulation with abundant weight and amount reduction, after necessarily to use a switching-mode ability supply.
This action cannot be accustomed in some countries for commercial-use. The columnist doesn’t accept any albatross for the anatomy as that ambit it will be applied.
Wednesday, November 5, 2014
USB Powered Audio Power Amplifier
This circuit of multimedia speakers for PCs has single-chip-based design, low-voltage power supply, compatibility with USB power, easy heat-sinking, low cost, high flexibility and wide temperature tolerance. At the heart of the circuit is IC TDA2822M. This IC is, in fact, mono-lithic type in 8-lead mini DIP package. It is intended for use as a dual audio power amplifier in battery-powered sound players. Specifications of TDA2822M are low quiescent current, low crossover distortion, supply voltage down to 1.8 volts and minimum output power of around 450 mW/channel with 4-ohm loudspeaker at 5V DC supply input.
An ideal power amplifier can be simply defined as a circuit that can deliver audio power into external loads without generating significant signal distortion and without consuming excessive quiescent current. This circuit is powered by 5V DC supply available from the USB port of the PC.
When power switch S1 is flipped to ‘on’ position, 5V power supply is extended to the circuit and power-indicator red LED1 lights up instantly. Resistor R1 is a current surge limiter and capacitors C1 and C4 act as buffers. Working of the circuit is simple. Audio signals from the PC audio socket/headphone socket are fed to the amplifier circuit through components R2 and C2 (left channel), and R3 and C3 (right channel)
When power switch S1 is flipped to ‘on’ position, 5V power supply is extended to the circuit and power-indicator red LED1 lights up instantly. Resistor R1 is a current surge limiter and capacitors C1 and C4 act as buffers. Working of the circuit is simple. Audio signals from the PC audio socket/headphone socket are fed to the amplifier circuit through components R2 and C2 (left channel), and R3 and C3 (right channel)
USB Powered Audio Power Amplifier Circuit Diagram:
Potmeter VR1 works as the volume controller for left (L) channel and potmeter VR2 works for right (R) channel. Pin 7 of TDA2822M receives the left-channel sound signals and pin 6 receives the right-channel signals through VR1 and VR2, respectively. Ampl i f ied signals for driving the left and right loudspeakers are available at pins 1 and 3 of IC1, respectively. Components R5 and C8, and R6 and C10 form the traditional zobel network. Assemble the circuit on a medium-size, general-purpose PCB and enclose in a suitable cabinet. It is advisable to use a socket for IC TDA2822M. The external connections should be made using suitably screened wires for better result.
Monday, November 3, 2014
Balanced Microphone Amplifier
We published a design for a stereo microphone preamplifier with balanced inputs and a phantom power supply. The heart of this circuit was a special Analog Devices IC, the SSM2017. Unfortunately, this IC has been discontinued. In its place, the company recommends using the pin-compatible AMP02 from its current product line. However, and again unfortunately, the specifications of this opamp make it considerably less suitable for use as a microphone amplifier.
By contrast, Texas Instruments (in their Burr Brown product line) offer an integrated instrumentation amplifier (type 1NA217) that has better specifications for this purpose. Incidentally, this IC is also recommended as a replacement for the SSM2017. It features internal current feedback, which ensures low distortion (THD + noise is 0.004 % at a gain of 100), low input-stage noise (1.3 nV/√Hz) and wide bandwidth (800 kHz at a gain of 100). The supply voltage range is ±4.5 V to ±18 V. The maximum current consumption of the 1NA217 is ±12 mA.
Balanced Microphone Amplifier Circuit diagram:
The gain is determined by only one resistance, which is the resistance between pins 1 and 8 of the IC. The circuit shown here is a standard application circuit for this instrumentation amplifier. R1 and R2 provide a separate phantom supply for the microphone connected to the amplifier (this is primarily used with professional equipment). This supply can be enabled or disabled using S1. C1 and C2 prevent the phantom voltage from appearing at the inputs of the amplifier.
If a phantom supply is not used, R1 and R2 can be omitted, and it is then better to use MKT types for C1 and C2. Diodes D1–D4 are included to protect the inputs of the 1NA217 against high input voltages (such as may occur when the phantom supply is switched on). R4 and R5 hold the bias voltage of the input stage at ground potential. The gain is made variable by including potentiometer P1 in series with R6. A special reverse log-taper audio potentiometer is recommended for P1 to allow the volume adjustment to follow a linear dB scale.
If a phantom supply is not used, R1 and R2 can be omitted, and it is then better to use MKT types for C1 and C2. Diodes D1–D4 are included to protect the inputs of the 1NA217 against high input voltages (such as may occur when the phantom supply is switched on). R4 and R5 hold the bias voltage of the input stage at ground potential. The gain is made variable by including potentiometer P1 in series with R6. A special reverse log-taper audio potentiometer is recommended for P1 to allow the volume adjustment to follow a linear dB scale.
The input bias currents (12 µA maximum!) produce an offset voltage across the input resistors (R4 and R5). Depending on the gain, this can lead to a rather large offset voltage at the output (several volts). If you want to avoid using a decoupling capacitor at the output, an active offset compensation circuit provides a solution. In this circuit, a FET-input opamp with a low input offset (an OPA137) is used for this purpose.
It acts as an integrator that provides reverse feedback to pin 5, so the DC output level is always held to 0 V. This opamp is not in the audio signal path, so it does not affect signal quality. Naturally, other types of low-offset opamps could also be used for this purpose. The current consumption of the circuit is primarily determined by the quiescent current of IC1, since the OPA137 consumes only 0.22 mA.
It acts as an integrator that provides reverse feedback to pin 5, so the DC output level is always held to 0 V. This opamp is not in the audio signal path, so it does not affect signal quality. Naturally, other types of low-offset opamps could also be used for this purpose. The current consumption of the circuit is primarily determined by the quiescent current of IC1, since the OPA137 consumes only 0.22 mA.
Friday, October 31, 2014
The monophonic 270 watt Double barreled Amplifier
This amplifier is the monophonic 270 watt Double barreled Amplifier. For the original article, I specified plus and minus 85 V dc power supply voltages. The voltage can be increased to about 93 V to obtain a power rating of 300 W. The amplifier can be built either as a stereophonic or a monoponic unit. My original amps were mono units because the heat sinks, transformer, and filter caps that I used were too large for a stereo amp.
The circuit described on this page is a modification of the original Double Barreled Amplifier. The circuit has been simplified somewhat. The circuit board layout is smaller and much more compact. The driver transistors now mount on the circuit board instead of on external heat sinks. And the circuit has the feedforward compensation that I describe for the Low TIM Amplifier.
If you build this amplifier, you must keep the wiring between the heat sinks and the circuit boards as short as possible if you dont want oscillation problems.
When you test the circuit boards before connecting the power transistors, temporarily connect a 10 ohm resistor in series with a 0.1 ufd capacitor from the loudspeaker output to the power supply ground.
The circuit described on this page is a modification of the original Double Barreled Amplifier. The circuit has been simplified somewhat. The circuit board layout is smaller and much more compact. The driver transistors now mount on the circuit board instead of on external heat sinks. And the circuit has the feedforward compensation that I describe for the Low TIM Amplifier.
If you build this amplifier, you must keep the wiring between the heat sinks and the circuit boards as short as possible if you dont want oscillation problems.
When you test the circuit boards before connecting the power transistors, temporarily connect a 10 ohm resistor in series with a 0.1 ufd capacitor from the loudspeaker output to the power supply ground.
The Circuit Boards
I do not have circuit boards for the Double Barrelled Amplifier. If you wish to build it, you must make your own. Two drawings show the parts layout on the board, one with circuit traces and one without. These are scaled by a factor of 1.5. The other shows the circuit traces only. All layout views are from the component side of the board. You must flip the layout for the foil traces over to obtain the solder side view. The circuit board measures 4 inches by 6 inches. To my knowledge, there are no errors in the layout. If you decide to use it, you should carefully check it for errors because I could have easily made a mistake.
I do not recommend that you make the circuit boards unless you have experience in doing it. A source of materials for making your own printed circuits can be found here. I have been told that their "Press and Peel Blue" product (not the wet stuff they sell) can be used to successfully make boards with traces as narrow as 0.01 inch. The smallest traces on the amplifier layout are 0.03 inch wide. The PnP Blue product is basically a transfer medium that allows you to transfer the toner image from a laser printer directly onto bare copper clad board and then etch it in FeCl3 (ferric chloride).
After you etch the board, the copper should be cleaned with steel wool, lightly coated with solder flux, and then "tinned" with a soldering iron and rosin core solder. Do not use a commercial tinning solution that you dip the board into. It is almost impossible to solder a board that is tinned with one of these products because they corrode very quickly. When you drill the board, you should use the correct size drill bit for the pads. The hole diameters I recommend are: small pads - 0.032 inch, medium pads - 0.040 inch, large pads - 0.059 inch, mounting holes - 0.125 inch. If you do not use a sharp drill bit, you can pull the pads off the board when you drill it.
Circuit Description
If you compare the Double Barreled circuit to the Low TIM circuit, you will see a lot of similarity between the two. Indeed, there is a Low TIM Amplifier embedded in the Double Barreled Amplifier. The major difference between the two is that transistors are added in series with those in the Low TIM circuit to form the Double Barreled circuit. By doing this, the voltage across the transistors is decreased so that the power supply voltage can be increased for higher output power.
Basically, the circuit description for the Low TIM Amplifier also applies to the Double Barreled Amplifier. The major difference between the two is the addition of transistors Q22 through Q31. Q22 is connected as a common base stage at the output of Q12. The two transistors form a cascode stage. The base of Q22 connects to the junction of R52 and R54. These two resistors are equal and are connected as a voltage divider between the loudspeaker output and the positive rail. This forces the base voltage of Q22 to float half way between the loudspeaker output voltage and the positive power supply rail. Similarly, Q13 and Q23 form a cascode stage. R53 and R55 force the base of Q23 to float half way between the loudspeaker output voltage and the negative power supply rail. The addition of Q22 and Q23 cause the collector to emitter voltages of Q12 and Q13 to be approximately one-half of what the voltages would be without Q22 and Q23.
Transistors Q24 and Q25 connect in series with the pre-driver transistors Q14 and Q15. The base of Q24 floats half way between the output voltage and the positive rail. The base of Q25 floats half way between the output voltage and the negative rail. The addition of Q24 and Q25 cause the voltages across Q14 and Q15 to be approximately one-half of what they would be without Q24 and Q25. Similarly, transistors Q26 through Q31 cause the voltages across Q16 through Q21 to be approximately one-half of what they would be without Q26 through Q31. By connecting the transistors in series in this way, the rail voltages can be increased for higher output power.
The basic construction details of the Low TIM Amplifier also apply to the Double Barreled Amplifier. There are two short circuit jumper wires that must be soldered on the circuit board. These are marked with a J on the layout. In addition, you must solder a short circuit jumper in place of C6B if you use a non-polar capacitor for C6A. This is explained in the parts list for the Low TIM Amplifier. Because there are eight output transistors, two main heat sinks per channel are required. Q18, Q20, Q28, and Q30 should be mounted on one and Q19, Q21, Q29, and Q31 on the other. Resistors R61 through R64 and wires connecting the collectors of Q18 and Q20 and the collectors of Q19 and Q21 mount on the heat sinks. These connect between lugs on the transistor sockets. The four bias diodes D1 through D4 can be mounted on either heat sink. It is not necessary to divide the diodes between the two heat sinks because both heat sinks will operate at the same temperature. I recommend setting the voltage across Q7, i.e. the voltage between the collectors of Q22 and Q23, so that that amplifier is biased at 120 mA. This will give the same quiescent power dissipation per heat sink as in the Low TIM Amplifier.
Testing the Circuit Boards
After you solder the parts to the circuit board, it is tested using the same procedure specified for the Low TIM circuit board. First, you must solder the short circuit jumper across Q7 and you must solder the 100 ohm 1/4 W resistors from the loudspeaker output to the emitters of Q16 and Q17. If you dont have a bench power supply that puts out plus and minus 85 to 93 V dc, you can test the circuit board at a lower voltage. I would prefer test voltages of at least plus and minus 50 V dc. An option is to connect bench power supplies in series to obtain the plus and minus 85 to 93 V dc. I have routinely connected two 40 V Hewlett Packard power supplies in series with the positive and negative outputs of a Hewlett Packard 50 V dual power supply, and I have never had any problems. To protect the circuit boards, you might want to put a 100 ohm 1/4 W resistor in series with the plus and minus power supply leads for the tests. The current drawn by the circuit should be low enough so that the voltage drop across these resistors is less than 1 V if nothing is wrong on the circuit board. There are 2 ground wires from the circuit board. Both must be connected when testing the boards.
I cant stress how important it is to be careful in testing a circuit board. Even simple errors can cause the loss of many expensive transistors. I always use current limited bench power supplies to test a circuit board before and after connecting the power transistors. I also bias an amplifier using current limited power supplies in place of the amplifier power supply. When I initially power up an amplifier with its own power supply, I always use a Variac variable transformer to slowly increase the ac input voltage from 0 to 120 V rms while observing the amplifier output on an oscilloscope with a sine wave input signal. If I see anything wrong on the oscilloscope, I turn the Variac to zero and try to diagnose the problem using the bench power supply. I never use a load on the amplifier for these tests.
Parts List
With the following exceptions, the parts for the Double Barreled Amplifier are the same as for the Low TIM Amplifier.
Capacitors
C10, C11 - 15 pF mica
C13, C14 - 100 uFd 100 V radial electrolytic
C21, C22 - 47 uFd 100 V radial electrolytic
C26, C27 - 270 pF mica
C28 - 0.01 uFd 250 V film
Transistors
Q1, Q2, Q5, Q7, Q9, Q10 - MPS8099 or MPSA06
Q3, Q4, Q6, Q8, Q11 - MPS8599 or MPSA56
Q23, Q24 - 2N3439
Q22, Q25 - 2N5415
Q26 - MJE15030
Q27 - MJE15031
Q28, Q30 - MJ15003
Q29, Q31 - MJ15004
Diodes
D5, D6 - 1N4934 fast recovery rectifier
D13 through D16 - 1N5250B 20 volt zener diode
Resistors
R13, R14 - 5.6 kohm 1 watt (This value is for 85 V power supplies. For other power supply voltages, the formula is on the Parts List page for the Leach Amp.)
R28, R29 - 200 ohm 1/4 watt
R30, R31 - 3.9 kohm 1 watt
R37 through R40 - 470 ohm 1/4 watt
R41 through R44 - 10 ohm 1/2 watt (changed 6/27/00)
R52 through R55 - 6.2 kohm 1 watt
R56 through R59 - 10 ohm 1/2 watt (changed 6/27/00)
R60 - 39 ohm 1/4 watt
R61 through R64 - 0.33 ohm 5 watt. These 4 resistors are mounted on the heat sinks between solder lugs on the power transistor sockets. The wires that connect the collectors of Q18 and Q20 and the collectors of Q19 and Q21 are also soldered between the lugs on the sockets. Keep all leads as short as possible and use insulation stripped from hookup wire around the bare leads of the resistors.
R65, R66 - 300 ohm 1/4 watt
Wednesday, October 29, 2014
600 Watt Quasi Amplifier With Mosfet IRFP460
ACTK 400/600 Watt
Two versions of a robust module capable of delivering high powwer for extended periods. The Actrk400 uses 6 n-channel Mosfets in the output stage to deliver around 400 watts into 4 ohms while the Actrk600 uses 12 n-channel Mosfets in the output stage to deliver power in excess of 600 watts into 4 ohms. One constructor has achieved almost 900 watts with the Actrk600 layout using 12 IRFP460 Mosfets.
ACTK Power Supply
Schmatic
Layout power supply
Final Set up And Adjustment
No attempt should be made to set up or test a power amplifier module that is not correctly mounted on
a heatsink. Make sure the main power supply is fused and the work area is clear. First check all your
work and make sure the output devices are insulated from heatsink. The set up is done without an
input or a load connected to the power amplifier.
1. Check the power supply is operating correctly and verify the rail voltages. Switch the power
supply off and check with a multimeter that the rail capacitors have discharged.
2. Using a multimeter measure the resistance of VR2 and set it for maximum resistance.
3. Correctly connect the ground lead, the two positive leads plus the negative lead to the power
amp module.
4. Remove the PCB fuses and replace with 100 ohm 5 watt resistors. Connect a multimeter that
is set to the 20 volt scale across the positive rail 100 ohm resistor.
5. Check that the power supply connections are correct one last time and switch on. If the
multimeter reading goes off-scale, turn off immediately and find the problem. Check also the
100 ohm 5 watt resistors; they may have gone open cct.
6. If everything seems ok adjust VR2 to set the output stage bias current, by measuring the
voltage across the positive rail resistor. Adjust for a reading of 4 volts per output FET pair. I.e.
For a 6 FET board set for a voltage of 12 volts. This equates to a bias current of 40mA per FET
pair or 120 mA total. For the 12 FET board set for a voltage of 24 volts.
7. If everything seems ok, check the output offset voltage and adjust VR1 to achieve an offset of
less than 10 mV. You will need to wait briefly between adjustments for the offset to settle.
8. All being well switch off, back off the bias control trimmer (VR2) and replace the 100 ohm
resistors with 10 ohm 1 watt resistors. Switch on again and re-adjust VR2 to get 0.4 volts per
FET pair.
9. Switch off, remove the resistors and put the fuses back in. Switch on, re-check the offset
voltage and adjust with VR1 if necessary.
The amp module is ready, connect the input and output and enjoy.
Read More..
Two versions of a robust module capable of delivering high powwer for extended periods. The Actrk400 uses 6 n-channel Mosfets in the output stage to deliver around 400 watts into 4 ohms while the Actrk600 uses 12 n-channel Mosfets in the output stage to deliver power in excess of 600 watts into 4 ohms. One constructor has achieved almost 900 watts with the Actrk600 layout using 12 IRFP460 Mosfets.
Actrk 600W schematic
ACTK 400W Layout
ACTK 600W Layout
Schmatic
Final Set up And Adjustment
No attempt should be made to set up or test a power amplifier module that is not correctly mounted on
a heatsink. Make sure the main power supply is fused and the work area is clear. First check all your
work and make sure the output devices are insulated from heatsink. The set up is done without an
input or a load connected to the power amplifier.
1. Check the power supply is operating correctly and verify the rail voltages. Switch the power
supply off and check with a multimeter that the rail capacitors have discharged.
2. Using a multimeter measure the resistance of VR2 and set it for maximum resistance.
3. Correctly connect the ground lead, the two positive leads plus the negative lead to the power
amp module.
4. Remove the PCB fuses and replace with 100 ohm 5 watt resistors. Connect a multimeter that
is set to the 20 volt scale across the positive rail 100 ohm resistor.
5. Check that the power supply connections are correct one last time and switch on. If the
multimeter reading goes off-scale, turn off immediately and find the problem. Check also the
100 ohm 5 watt resistors; they may have gone open cct.
6. If everything seems ok adjust VR2 to set the output stage bias current, by measuring the
voltage across the positive rail resistor. Adjust for a reading of 4 volts per output FET pair. I.e.
For a 6 FET board set for a voltage of 12 volts. This equates to a bias current of 40mA per FET
pair or 120 mA total. For the 12 FET board set for a voltage of 24 volts.
7. If everything seems ok, check the output offset voltage and adjust VR1 to achieve an offset of
less than 10 mV. You will need to wait briefly between adjustments for the offset to settle.
8. All being well switch off, back off the bias control trimmer (VR2) and replace the 100 ohm
resistors with 10 ohm 1 watt resistors. Switch on again and re-adjust VR2 to get 0.4 volts per
FET pair.
9. Switch off, remove the resistors and put the fuses back in. Switch on, re-check the offset
voltage and adjust with VR1 if necessary.
The amp module is ready, connect the input and output and enjoy.
Tuesday, October 28, 2014
250mW 16 dB VHF amplifier Circuit diagram
A high efficiency simple 2-transistor VHF amplifier electronic circuit project can be designed using this electronic circuit diagram . This VHF amplifier electronic circuit has a very high efficiency of about 16dB gain, and requires no tuning or alignment procedures. Wideband techniques have been used in the design and the circuit is equipped with a "lowpass" filter to ensure good output spectral purity. This VHF power amplifier circuit is specifically designed to amplify the output of 7mW to 10mW WBFM transmitters to a final level of 250mW to 300mW, after the filter.
The output of this stage is around 70mW of RF power.
The transistor is biased by means of R5, R6 and L6, and the residual DC current is set by R4. The input signal is coupled by C9 to the Base of the transistor.
The input signal from Q1 is coupled to the Base of Q2 via C7.The 78L08 voltage regulator is used to regulate the supply voltage to Q1 and the bias votages to both Q1 and Q2 so that the output RF power is relatively constant, even with large variations of supply voltage.
The output of the amplifier is filtered with a low-pass filter to reduce the output spurious and harmonic content.
The output filter consists of C3, C4, L1 and L2.
This RF power amplifier must be powered from a simple 12 volts DC power supply circuit.
![]( "250mW")
The output of this stage is around 70mW of RF power.
The transistor is biased by means of R5, R6 and L6, and the residual DC current is set by R4. The input signal is coupled by C9 to the Base of the transistor.
The input signal from Q1 is coupled to the Base of Q2 via C7.The 78L08 voltage regulator is used to regulate the supply voltage to Q1 and the bias votages to both Q1 and Q2 so that the output RF power is relatively constant, even with large variations of supply voltage.
The output of the amplifier is filtered with a low-pass filter to reduce the output spurious and harmonic content.
The output filter consists of C3, C4, L1 and L2.
This RF power amplifier must be powered from a simple 12 volts DC power supply circuit.
Monday, October 27, 2014
Input Stage Amplifier OPA134PA
OPA134PA Input Stage Amplifier Circuit Design schematics, box file middle name : OPA134PA Input Stage Amplifier Circuit. You are able to click on the picture to meet first size image. I constantly anticipation to facilitate this OPA134PA Input Stage Amplifier Circuit design schematics design pictures are able to help you at the same time as reference guide to build your DIY project!
Read More..
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| Input Stage Amplifier |
Thursday, October 23, 2014
70 Watt MOSFET Audio Amplifier
This is use the MOSFET power amplifier circuit, amplifier circuit has a very good sound quality. With the noise is quite small, thus making the amplifier circuit is suitable for you to try. Heres the circuit.
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| Click to view larger. |
150 watts power amplifier circuit
Amplifier circuit is 150 watts power amplifier circuit is quite simple.
This circuit requires only 5 pieces of transistors as the main component of reinforcement. There is no equalizer option on this amplifier circuit because it can be said of this series is very simple, so do not you compare it with that sold in the market which are usually equipped with various sound system and equalizer settings.
This circuit requires only 5 pieces of transistors as the main component of reinforcement. There is no equalizer option on this amplifier circuit because it can be said of this series is very simple, so do not you compare it with that sold in the market which are usually equipped with various sound system and equalizer settings.
But to add to your collection circuit, this circuit is fairly easy and inexpensive to make and maybe one day you may need as a weak signal booster from your electronic circuit. Or you can also make this amplifier as an amplifier of high frequency signal from the output circuit animal repellent and I guarantee the results are very satisfactory.
Power supply required is two-polarity power supply is + - 45 volts. Maximum power that can be obtained by this amplifier circuit is around 150 watts. As the volume control you can add potensio or variable resistor 10 Kohm in series at the input. Use dispasi loudspeaker with 150 watts power. Use a heatsink on the transistor-transistor driver loudspeaker or amplifier late as Q1 and Q2.
Friday, September 12, 2014
Simple Mosfet Buffer Amplifier Wiring diagram Schematic
This is a Simple Mosfet Buffer Amplifier Circuit Diagram, A MOSFET is used as a wide-band buffer amplifier. T1 is wound on a toroid of approximately /f diameter, with material suitable for frequency (usually 1- to 20-MHz range). The turns ratio should be about 4:1 depending on load impedance. Typically, at 4 MHz, there are 18 turns on the primary, 4 turns on the secondary, and the stage gain is about 14-dB voltage (ZL - 50 ).
Simple Mosfet Buffer Amplifier Circuit Diagram
LM317 Amplifier Circuit
You probably know with the purpose of LM317 IC is used being an changeable voltage manager, but did you know it can take place used as an audio amplifier? This is a taste A audio amplifier built with LM317 so as to delivers a utmost 1W audio power.
manipulate a worthy heatsink pro the LM317 IC and adjust the 5K inconsistent resistor so with the aim of you allow 4.5V on 10Ω resistor (otherwise LM317 pin 2, Vout).
Thursday, September 11, 2014
LM3886 Audio Amplifier 1 x 108W
LM3886general description:
According to National Semiconductor, the LM3886 is a high performance 150W Audio Power Amplifier with Mute. The performance of the LM3886, say NS, utilizing its Self Peak Instantaneous Temperature (°Ke) (SPIKe) protection circuitry, puts in a class above discrete and hybrid amplifiers by providing an inherently, dynamically protected Safe Operating Area (SOA). The LM3886T comes in an 11 (staggered-) lead non-isolated TO220 package.We put the LM3886T schematic and an existing printed circuit board as a basis. For test purposes, the prototype of the amplifier was powered by a stabilized ±35-V supply. A maximum undistorted output power of about 63 watts into 8 ohms was obtained at a drive level of 1 Vrms. Dropping the load impedance to 4 ohms pushed the output power to no less than 108 watts. In practice, these power levels can be taken to mean ‘music power’, but do remember that the amplifier will not normally be powered from a regulated supply!
Great attention should be paid to the cooling of the amplifier IC. The cooling capacity offered by a heatsink as specified in the parts list is really only sufficient for load impedances of 6 ohms or more. Even if a heatsink with a thermal resistance lower than 1 K/W is employed, the amplifier IC will cause a ‘hot spot’ on the heatsink surface where the actual thermal resistance is much higher locally than the specification! With this in mind, it is recommended to drop the supply voltage to about ±30 V if the amplifier is used to drive a 4-ohm load. Also, bear in mind that heatsink isolating materials like mica and even ceramics tend to raise the thermal resistance by 0.2 K/W to 0.4 K/W. The metal tab at the back of the IC is at the negative supply potential.
Boucherot network C6-R6 is not normally required in this application, and should be omitted unless the amplifier is found to be unstable as a result of an application which is widely different from the one shown here. Populating the amplifier board itself will be a piece of cake, and most of the time required to build the amplifier will go into drilling, cutting, mounting and isolating the heatsink. Note that the radial electrolytic capacitors are rated at 40 volts, so you have to make sure that the supply voltage can never exceed that level. The performance of the prototype amplifier built and tested in our design lab is expressed by the Specifications box.
LM3886 circuit diagram:
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| LM3886 circuit diagram |
LM3886 layout, pcb:
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| LM3886 layout and pcb |
LM3886 part list:
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| LM3886 partlist |
Datasheet for LM3886: Download
Wednesday, September 10, 2014
4 20 Volts Amplifier Circuit
This is an audio amplifier circuit based on IC, and IC were used that MPC563 with minimal output 6W, with impedance of 4 Ohm. Supply Voltage Minimum 4 Volt DC and a maximum voltage to 20 Volts DC. See him under this Scheme.
| 4 - 20 Volts Amplifier Circuit |
Tuesday, September 9, 2014
100 watts Symasym5 Power Amplifier
Symasym5, is a "cute" power amplifier, designed with quality but still low price in mind. This resulted in a ClassAB BJT amplifier, using only TO92 transistors for input and VAS, with a reasonable part count. The topology used is well known and consist of a single diffamp for input, plus a 2nd diffamp with current mirror for VAS. This is followed by normal darlington EF outputstage using modern high beta devices. The circuit uses large amounts of feedback over the whole audioband and an unconventional feedback compensation scheme. Right now symasym is designed to be driven directly from a CD/DVD-player, simply place a 22k poslog stereo pot between player and symasym. (as voltage divider)
Update
The at least change is to reduce C14 from 22pF to 10pF, but i recommend to follow Pavels advice. I recommend C14 with 10pF also for MJLs, this increases safety margin. Do not forget to read Pavels Review! A very promising evaluation of the qualities to be expected from symasym. Thanks Pavel ! Another update are the resistors R31/32 to be increased from 22ohm to 47ohm.
Symasym5_3 is an update of v5.2, with an improved board layout concerning power gnd, resulting in lower thd for high frequencies, giving more clarity in sound. The Page for symasym5_2 still exists.
If the gain is too high because symasym is driven from preamp, R30 can be increased from 499ohms to 1k, but in this case R16/19 (22 or 33 ohms, not on schematic, REs to Q1/2) are required to keep feedback at same level and
| 100 watts Symasym5 Power Amplifier |
Some Specs :
- THD: ~0.005% (measured) simd: 0.002%
- Power into 8ohm: 60 watts
- Power into 4ohm: 100 watts
- Gain: 32dB (~1:40) full output at 0.7v input (0.5v rms)
- Feedback: 57dB
- GainBandWidth: ~400Mhz
- Slewrate: ~20v/us (symetrical)
- Supply voltage: +/- 36v
- Biasing: 55ma, ~12mv across a single 0.22 ohm
- Measurings: RMAA Symasym5 The measuring setup itself is far from perfect, but gives a good idea !
- Frequency response: 3.2hz to 145khz (-1db) using 4.7uf input cap
- Phaseshift at 10khz: <3°
- More will follow !
Schematic
TDA8560Q Audio amplifier 2x40W
TDA8560Q general description:
Unfortunately, some of the proposed scheme in the network and even a scheme recommended by the developer (Philips), fail to achieve the desired result. As an example of how not to suggest that you include the TDA8560 material published on Online Soldering: Car Amplifier 2x40 Watt (I should note that everything except the input circuits and the number of points on diet, still deserves attention). the initial inclusion of IMS (at power up, the load is connected and there is no input signal) can throw you into a state of perplexity / mild shock (it depends on the degree of hope is for your TDA). Chip is unstable, there are noises when the input signal is amplified last weakly and passed with distortions. IC bypass surgery fixed resistor at the input, the other measures in consultation with the source device does not help. Why and what to do? Really caught Palen chip and will have to buy a new one? Not so fast! The fact that Philips did not include measures to prevent the self-excitation of the IC, but I think they know about it, but do not tell anyone (not good, gentlemen!) Rid chip excitement can (and should) in a way that is not described here. This is so far, my little secret. Usually TDA 8560 include approximately recommend the following scheme: TDA8560Q Audio amplifier 2x40W
TDA8560Q Features:
- Supply voltage: 6 - 18; typical 14.4 V.
- The peak output current: 7.5 A.
- The current in idle mode: 120 mA.
- Long-term power output, with
- RL = 4 ohms, THD = 10%, F = 1 kHz, 25 W,
- RL = 2 ohms, THD = 10%, F = 1kHz: 40W.
- Voltage gain, Au: 40 dB.
- Input Impedance: 30 ohms.
- Input Sensitivity: 100 mV.
- Frequency response: 20 - 20000 Hz.
- Requires very few external components
- High output power
- Low output offset voltage
- Fixed gain
- Diagnostic facility (distortion, short-circuit and temperature detection)
- Good ripple rejection
- Mode select switch (operating, mute and standby)
- Load dump protection
- Short-circuit safe to ground, to VP and across the load
- Low power dissipation in any short-circuit condition
- Thermally protected
- Reverse polarity safe
- Electrostatic discharge protection
- No switch-on/switch-off plop
- Flexible leads
- Low thermal resistance.
TDA8560Q amplifier diagram, circuit:
TDA8560Q layout:
Datasheet for TDA8560Q: Download
RF amplifier protection
RF amplifier protection
I have developed the protection circuit for the EB104 amplifier I am working on, after I finally had some time to design and test a few models. The main requirements have been:
- protection in case of high temperature;
- protection in case of high SWR;
- protection in case of wrong output filter selection;
- simple design (i’m a fan of the whole K.I.S.S. rule of thought), able to work in strong electromagnetic fields, reliable, inexpensive.
Because i will be using the same directional coupler i have used in the SWR meter (the one made on PCB) wich is directly influenced by the signal frequency, and because i want full HF coverage, i cannot just measure the reflected signal and make a circuit cut the amplifier when it goes over a limit; on 28Mhz the coupler generates roughly 4 times more voltage that let’s say in 7Mhz. So a system that compares direct and reflected signal and triggers when the latter is percentually too high was needed, therefore an operational amplifier was the natural choice. This will solve the SWR problem, and because the directional coupler will sit between the amplifier output and the low-pass filters, it will also trigger when a wrong band is selected.
The thermal problem will be even more easy to fix, i will use a NTC thermistor in a resistive divider; the second operational amplifier from the LM358 IC I have chosen to use will just compare the voltage from the resistive divider to a preset one, and will trigger when the thermistor’s value gets too small.
As usual, it’s much easier to understand when pictured:
![RF]()
The 5V stabilizer LM7805 is there to ensure good separation, and the BC107 transistor is used to increase current capabilities on the output. Parts list:
C1 – 100uF / 16V
C2 – 470uF / 6.3V
C3 … C10 – 10nF ceramic
R1, R4 – 470 ohm
R2 – 1 Kohm
R3 – 10 Kohm
VR1, VR2 – 10 Kohm
D1 … D4 – 1N4148
The circuit will trigger once one of the two described conditions will take place, and will remain like this until power is removed for 10 seconds, due to D1 or D4 diodes. A LED connected between LED1 + and LED1 – points will signal SWR protection enabled, and a LED connected between LED2+ and LED2 – will signal thermal protection enabled. TH+ and TH- will be connected to a 1Kohm NTC thermistor wich will be placed on the heatsink, as close to the amplifier’s power transistors as possible, and the FWD and REF points will be connected to a SWR sensing board like the one described in the SWR meter article. For reliable operation, low-pass filters on both FWD and REF lines might be needed, made from a series 1Kohm resistor and a 10 uF / 16V capacitor to ground.
There are many ways in wich the amplifier might be stopped from working once these protections trigger. Switching back the RX/TX relay while in full operation might be dangerous (for a second both transmitter and amplifier will work without a load) plus the relay might be damaged. The simple way is to cut down the power of the amplifier by removing the gate bias, by simply connecting the BC107′s collector (BIAS point) to the bias voltage regulator’s reference circuit (pin 5 of MC1723CP in the Eb104 schematic). This will still allow you to remain on the air, the transmitter will see the correct impedance on the amplifier’s input and the amplifier’s finals will be able to handle even infinite SWR and the heatsink will get the chance to cool down due to running in low power mode. SSB or AM work will be a problem, because the amplifier will work in C class now.
This has been tested with 100W on both antenna and dummy load, it’s working OK, the real test will be when the rest is finished though.
Read More..
I have developed the protection circuit for the EB104 amplifier I am working on, after I finally had some time to design and test a few models. The main requirements have been:
- protection in case of high temperature;
- protection in case of high SWR;
- protection in case of wrong output filter selection;
- simple design (i’m a fan of the whole K.I.S.S. rule of thought), able to work in strong electromagnetic fields, reliable, inexpensive.
Because i will be using the same directional coupler i have used in the SWR meter (the one made on PCB) wich is directly influenced by the signal frequency, and because i want full HF coverage, i cannot just measure the reflected signal and make a circuit cut the amplifier when it goes over a limit; on 28Mhz the coupler generates roughly 4 times more voltage that let’s say in 7Mhz. So a system that compares direct and reflected signal and triggers when the latter is percentually too high was needed, therefore an operational amplifier was the natural choice. This will solve the SWR problem, and because the directional coupler will sit between the amplifier output and the low-pass filters, it will also trigger when a wrong band is selected.
The thermal problem will be even more easy to fix, i will use a NTC thermistor in a resistive divider; the second operational amplifier from the LM358 IC I have chosen to use will just compare the voltage from the resistive divider to a preset one, and will trigger when the thermistor’s value gets too small.
As usual, it’s much easier to understand when pictured:
C1 – 100uF / 16V
C2 – 470uF / 6.3V
C3 … C10 – 10nF ceramic
R1, R4 – 470 ohm
R2 – 1 Kohm
R3 – 10 Kohm
VR1, VR2 – 10 Kohm
D1 … D4 – 1N4148
The circuit will trigger once one of the two described conditions will take place, and will remain like this until power is removed for 10 seconds, due to D1 or D4 diodes. A LED connected between LED1 + and LED1 – points will signal SWR protection enabled, and a LED connected between LED2+ and LED2 – will signal thermal protection enabled. TH+ and TH- will be connected to a 1Kohm NTC thermistor wich will be placed on the heatsink, as close to the amplifier’s power transistors as possible, and the FWD and REF points will be connected to a SWR sensing board like the one described in the SWR meter article. For reliable operation, low-pass filters on both FWD and REF lines might be needed, made from a series 1Kohm resistor and a 10 uF / 16V capacitor to ground.
There are many ways in wich the amplifier might be stopped from working once these protections trigger. Switching back the RX/TX relay while in full operation might be dangerous (for a second both transmitter and amplifier will work without a load) plus the relay might be damaged. The simple way is to cut down the power of the amplifier by removing the gate bias, by simply connecting the BC107′s collector (BIAS point) to the bias voltage regulator’s reference circuit (pin 5 of MC1723CP in the Eb104 schematic). This will still allow you to remain on the air, the transmitter will see the correct impedance on the amplifier’s input and the amplifier’s finals will be able to handle even infinite SWR and the heatsink will get the chance to cool down due to running in low power mode. SSB or AM work will be a problem, because the amplifier will work in C class now.
This has been tested with 100W on both antenna and dummy load, it’s working OK, the real test will be when the rest is finished though.
source:link
Simple 50 W Electronic Amplifier Wiring diagram Schematic
This electronic amplifier project is an IC amplifier module from ST Microelectronics, the TDA7294. It is intended for use as a top quality audio class AB amplifier in hi-fi applications. Its low noise and distortion, wide bandwidth and nice output current capability, enabling it to supply high power in to both four ohm and 8 ohm lots. Its both short schema and thermal protection.
With the addition of a handful of parts and an appropriate power supply, this module will deliver over 50W RMS in to four or 8 ohms-with < 0.1% Total Harmonic Distortion (THD) and < 0.1% Inter-modulation Distortion (IMD). It is also suitable as a replacement power amp stage, or upgrade for plenty of existing amplifiers of between 30W-50W, provided they have an appropriate dual supply, & most do.
With the addition of a handful of parts and an appropriate power supply, this module will deliver over 50W RMS in to four or 8 ohms-with < 0.1% Total Harmonic Distortion (THD) and < 0.1% Inter-modulation Distortion (IMD). It is also suitable as a replacement power amp stage, or upgrade for plenty of existing amplifiers of between 30W-50W, provided they have an appropriate dual supply, & most do.
The Specifications of the electronic amplifier project there are:
D.C. Input : 35V
Output power : > 50W RMS, 4-8 ohm load.
Gain : 24 dB (30dB modification)
Input sensitivity : one.3V for 50W, 8 ohm
Signal-to-Noise ratio : > 95 dB, (>105 dBA)
Frequency response : approx. 20Hz - 200kHz, �3 dB
Slew rate : > 10V/uS
THD : < 0.01%, 1W-40W, 1kHz
IMD : < 0.01%, 1W
D.C. Input : 35V
Output power : > 50W RMS, 4-8 ohm load.
Gain : 24 dB (30dB modification)
Input sensitivity : one.3V for 50W, 8 ohm
Signal-to-Noise ratio : > 95 dB, (>105 dBA)
Frequency response : approx. 20Hz - 200kHz, �3 dB
Slew rate : > 10V/uS
THD : < 0.01%, 1W-40W, 1kHz
IMD : < 0.01%, 1W
The maximum supply voltage of the IC is +/- 40V. However the maximum dissipation of the IC can be exceeded even at a lower voltage. Therefore the supply voltage used require not be over +/- 35V. This can be constructed using a 50V middle tapped-transformer, a diode bridge rated at 5A (min.) & a pair of electrolytic capacitors, as shown below. A lower secondary voltage transformer could even be used but the reduced DC voltage will lead to less power output in to 8 ohms. You can still receive 50W in to four ohms with only 24V supply rails.
A 36V C.T. transformer will give you approx +/- 25V rails. The-mains transformer used ought to be rated at a maximum of 80VA. In the event you require to run modules in a stereo amplifier you can use a common power supply. In this case the transformer ought to be rated at 150VA or greater.
A 36V C.T. transformer will give you approx +/- 25V rails. The-mains transformer used ought to be rated at a maximum of 80VA. In the event you require to run modules in a stereo amplifier you can use a common power supply. In this case the transformer ought to be rated at 150VA or greater.
Electronic Amplifier Circuit Diagram Description
Most of the schemary is contained within the IC module. The input signal is applied to pin three by capacitor C1 & low-pass filter R1/C2. The filter improves the pulse response & helps cease RF signals. The lower -3dB point is determined-by R2/C1 & R4/C3. This is about 20Hz for the values used. The upper -3dB point is over 200kHz. C7/C8 & C9/C10 provide additional power supply filtering or decoupling.
Simple 50-W Electronic Amplifier Circuit Diagram
Simple 50-W Electronic Amplifier Circuit Diagram
R3/R4 are the feedback resistors. The gain is 1+R3/R4 which is approx 16 times, or 24dB. In case you need to increase the input sensitivity you may alter the resistors to suit. Changing R3 to 22k would increase the gain to 30dB and lower the input-required for 50W in to 8 ohm, to 0.6V, without affecting performance much. In case you reduce the worth of R4 you will also need to increase C3 to maintain bass response, as this sets the feedback low frequency roll off.
Pin ten is a mute input and pin 9 provides a standby mode. Muting ought to always happen before standby mode is selected. Connecting these pins permanently to the supply rail ensures that the amplifier comes on immediately on power up. Any switch-on clicks may be eliminated by increasing the time constants of R5/C4 and R6/C5 if necessary.
Make definite that a heavy duty heat-sink rated at least one.4 degree C/W or better is used.
Pin ten is a mute input and pin 9 provides a standby mode. Muting ought to always happen before standby mode is selected. Connecting these pins permanently to the supply rail ensures that the amplifier comes on immediately on power up. Any switch-on clicks may be eliminated by increasing the time constants of R5/C4 and R6/C5 if necessary.
Make definite that a heavy duty heat-sink rated at least one.4 degree C/W or better is used.
Monday, September 8, 2014
RF Amplifier circuit with 2SC1970 2N4427
RF power amplifier circuit of this work is based on the transistor 2SC1970 and 2N4427. The set output power of 88-108 MHz FM RF Amplifier With 2SC1970 is about 1.3W and the input driver is 30-50mW. RF driver amplifier circuit uses a 2N4427 and its power amplifier using a transistor 2SC1970.
At the time of the amplifier circuit tuning FM 88-108 MHz RF Amplifier With 2SC1970 should use the power meter / watt meter or SWR or RF field can also use the meter. RF amplifier circuit can work from the frequency of 88-108 MHz.
At the time of the amplifier circuit tuning FM 88-108 MHz RF Amplifier With 2SC1970 should use the power meter / watt meter or SWR or RF field can also use the meter. RF amplifier circuit can work from the frequency of 88-108 MHz.
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| RF Amplifier |
Circuit of 88-108 MHz FM RF Amplifier With RF 2SC1970 can radiate far enough. At the time of tuning you should use a 50 Ohm dummy load. For the input signal should be installed to regulate the VR level so as not to over-modulation (30-50mW).
Sunday, September 7, 2014
200W Audio Amplifier Circuit
Circuit description:
Connecting two TDA2030 thru cheap power transistors we can create a amplifier wich can deliver a higher power. With the components value from the schematic the total amplifier gain is 32 dB. The speaker can be 2 ohm instead of 4 ohm if we use the TIP transistors. TDA 2030 is produced by SGS Ates and is a complete audio amplifier. AB class of the final amplifier cand deliver up to 14W on 4 ohm at a +-14V power supply. With a proper designed power supply this audio amplifier can output 200W.
Circuit diagram:
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| Circuit diagram for 200W Audio Amplifier |
Part list
- IC1, Ic2 TDA 2030
- T1, T3 = BD 250, TIP 36
- T2,T4 = BD 249, TIP 35
- D1 … D4 = 1N4001
600 Watt Quasi Amplifier With Mosfet IRFP460
ACTK 400/600 Watt
Two versions of a robust module capable of delivering high powwer for extended periods. The Actrk400 uses 6 n-channel Mosfets in the output stage to deliver around 400 watts into 4 ohms while the Actrk600 uses 12 n-channel Mosfets in the output stage to deliver power in excess of 600 watts into 4 ohms. One constructor has achieved almost 900 watts with the Actrk600 layout using 12 IRFP460 Mosfets.
| 600 Watt Quasi Amplifier With Mosfet IRFP460 |
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