Volt Stabilizer

Car Voltage Stabilizer Assembly

O2 meter for car circuit

Welcome back to Free circuit dot com ,Today i would like to show you in about circuit for car .

So,All really knows how to customize the level of production with an LM3914 LED?

What I’m trying to do is read a signal from a pressure sensor in my car exploded and show a more or less accurate reading of impulse (psi) with 10 LEDs. Here is the map of psi Volt:

Electronic Part

-20 = 3.4 V
-10 = 3.1 V
0 = 2.9 V
5 = 2.7 V
10 = 2.4 V
15 = 1.8 V
20 = 1.4 V

Assembly Picture

So, more or less show you need the LM3914 to ~ 1.5 volts – 3 volts to the LED. I know it has something to do with the use of resistance in some of the pins, but I can not understand. Any help is welcome! Thank you.

The O2 sensor. As a D15 B12 Nissan or Honda engines. Must be the only O2 sensor wire. No cable 3 or 4, as these O2 sensors require heating.

Solid State Relays Circuit

Welcome to Free circuit dot com ,today we have classic circuit to implement solid state relay in your electronic project .

Solid state relays are almost everywhere these days, but they are very expensive. So, your efforts to build their own salary. Especially since it’s only a few parts and circuit simple and straightforward. Solid state relay is not really at all relays. There are no “relay” is available only with electronics, connection works. It works well as a relay, you can use low voltage higher and better. “Relay” between 115/220V AC wires in place, although it was customary, the neutral conductor and leave unchanged phases and neutral.

As long as no voltage (left in picture), the phototransistor TIL111 blocks of energy, and thus is not available. To ensure that the base TIL111 is fed to the transmitter (s) through the 1M resistor. This method prevents the base of transistor BC547B will be low and remains biased ‘on’. Collector is low and the gate (g) TIC106M thyristor, which is still in the country, “off”. 4-diode bridge rectifier circuit has no power apart from a small base and collector current BC547B, which is not enough to turn over the 330-ohm resistor TIC226M triac. Current “Load”, is very small.

With an input voltage, say 5 volts, the diode in the TIL111 lights up and activates the phototransistor. The voltage drop 1MEG ohm resistor in series with 22K resistance increases demand, which block the BC547B transistor. Collector current of the fact that the AC voltage falls below a certain value, which is VA. This ensures a sufficiently large voltage drop across the resistor 330 ohms triac switches ‘on’. The voltage on triac is currently only a few volts, so that practically the whole 115/220 AC voltage on the “Upload”.

The triac is a 100nF capacitor and impedance of 47 ohms, 100nF capacitor for the 330 ohm resistor is to protect the triac to be undesirable distortions caused by small peaks. To create the possibility of this circuit with different voltages to be switched, added BF256A FET. The FET acts as a current source from the source (s) with a gate (g). This means that this FET determines the current TIL111, regardless of the input voltage (up to a certain tolerance, of course). 1N4148 diode is to protect the circuit from reverse polarity.
(Tony: TIL111 is a so-called “optical coupling” with NPN output and can be replaced with NTE3042)

Good point line, as is the separation of AC and DC voltage, so this circuit is used in many applications, about 1.5 kW, when the triac is mounted on the large size of the cooling fins.
“M” appears Triac means it’s 600volt type, “D” for 400V. So be sure to go to the M-type.

NTE replacement for this circuit are 600volt types which are more than sufficient for our 110/115VAC. Even if you decide to print for this circuit is enough space between the lines AC and non AC these tracks to be close.

DVD to RF modulator circuit

Welcome back to Free Circuits dot com,It is long time to see you as i’m busy in my working ,OK first of all,
This circuit today is a RF modulator which can be used for moduling of video signals .
P1 control the Light and P2 control the contrast of video signal.
RF modulated output signal can be received on VHF band ( about 189 MHz ).

Power Amp-TDA 7294

Welcome back to Free Circuit dot com again,Today ,I would like to present a small audio amplifier circuit with TDA7294.

You can follow by PCB thus as my post.

The described circuit uses two TDA7294 for use in stereo (2 x 80 watts) and bridge mode (1x 180 watts), configure this setting only four drivers.

To facilitate the installation of each fuel. The performance is a kind of symmetry with a simple bridge rectifier 6A, and two large electrolytic capacitors, which 10000μF 22000μF/50v. This power supply for two modules. The processor is recommended 22-0-22 to 28-0-28 / 5 A, depending on the quality of the transformer is at least 6 amps is recommended.

Parts Layout PCB

Amp TDA7294 PCB

The TDA7294 is a monolithic integrated circuit in MULTIWATT15 package for use as audio class AB amplifier in Hi-Fi field applications (stereo, powered speakers, car, high-end TV) is provided. Many thanks to the wide range of voltage and current capacity he is able to offer the highest property taxes in both 4Ω and 8Ω, to offer even in the presence of poor supply regulation, with the rejection of high-voltage power supply. The built-in mute with delay sounds easier to avoid the remote mode off.

preamp power supply

This is IRRESPONSIBLE and DANGEROUS!!

Welcome back to Free circuit dot com again,today i would like to present the preamp power supply circuit.

this circuit is small and easy to assembly,we will use IC regulator 7915 and 7815 for main control voltage.

About all capacitors are filter noise and frequency.

We will take diodes to allow an electric current to pass in one direction (called the diode’s forward direction), while blocking current in the opposite direction

DC to DC Converter with 450Watt

For developper who would like to power supply for your amplifier or other load.Circuit today will be show you in DC to DC converter circuit with 450 Watts.

+/- 50 Vdc for Output Voltage , Voltage adjustable between 47-55 Vdc.

No problem in output Voltage drop when connect load.

We have verified the circuit already. For more detail ,Could you look at the picture thus as below.

DC to DC 50V 450W Circuit

Mosfet Amplifier K1058 circuit

Welcome back to Free circuit dot com,We would like to present audio amplifier circuit as this amplifier consists of two completely separate mono amp for each channel has its own power supply, so zero inter-channel crosstalk, a common phenomenon in amplifiers, the same diet. 0 – - 40VAC at 640VA To the full power any 40VAC transformer should be evaluated to obtain. Unlike many designs, referring to the capacitors to supply the current peaks, I prefer the raw power available from the transformer, have resulting in faster transients.

Mosfet 200W Class A PCB

Although RAS-300 specifications moderate, if they immediately hear the huge reserves of power available and not cause of fear that something, this would give a very loud while driving amplifiers. You hear nothing but the truth without distortion at any level, and I guarantee you that this amp the best qualities of the connected devices reveal.

Mosfet 200W Class A Parts Assembly

Digital weight circuit

Welcome back to free circuit dot com,today we are present circuit for digital weight circuit .

This uses a potentiometer as the weight sensing with seven segment LED element.

An moving object on the scale of the potentiometer wiper, an amount proportional to the weight.

Conversion led the wiper voltage of digital information, decode and display interfaces to the numerlc.

Microphone preamp circuit

Welcome back to free circuit dot com ,today we have amplifier for microphone with transistor number BC549,BC547 for drive signal.

As this is a simple microphone preamplifier circuit between microphone and stereo amplifier can be used.
The circuit amplifier microphone suitable for use with a normal stereo amplifier line / CD / aux / tape inputs.

The microphone preamplifier can be both dynamic and electret microphone inputs (preamplifier provides foe electret microphone elements). The idea of this circuit is provided that the design as easy as possible for easy build.
Which was my goal when I make a simple external microphone preamplifier for my mixer needed. The behavior of the circuit is nothing better, but with many not so serious projects are used.

Monostable circuit

Welcome to free circuit dot com,For the last article in this series, we may be unstable a cycle which has no stable output state. In this post circuit we will show the monostable circuit, which has a stable state.

The waveforms in Figure 1 show the effect of a monostable. A monostable circuit produces a pulse of a certain length (time T) in response to a trigger input such as a pushbutton. The output of the circuit remains in the low position to a trigger input, does the name “Mono”, “stable condition”.

This type of circuit is ideal for use in a “push-to-operate” in a model system for exhibitions. A visitor can press a button to a model mechanism in motion, and the mechanism will automatically after a certain time. Another use of the circuit “the bounce” an important contribution to a digital IC – this application will be explained later in this article.

battery discharger circuit

Free circuit dot com today,I will be present battery discharger circuit with IC LM3900 to control process its.  

   The reason I designed this dischargers are many, but I am a typical example for this list. A size batteries cost modeler for 14 hours, then goes to the field for a fly. He then rest for 1 week, then cost batteries for 14 hours and fly back. The third time he repeated the procedure, then wonders why his plane has an important argument for the airstrip. The problem with this method is that it battey a suit rechargeing after the first week, in an unknown state of charge. The second and subsquent fees are grossly overcharging the batteries. If they are full, are Ni-Cad batteries gasification start from the electrolyte and a sealed battery, the electrolyte (as opposed to a car battery), never to be refilled. Over-charging the batteries deteriorated significantly and it reduces their capacity dramatically.

Parts List:
Resistors: 10K(7), SOT 16K4 & 6.9K, 470 Ohm(2), 4K7(2), 1K(3), 47 ohm/5W, 47ohm(2 parallel).
Capacitors: 10uF (electrolytic), 0.1uF (ceramic).
Transistors: BD681(2), BC548(1)
Diodes: 1N4001(2)
Led’s: Red, 5mm(2)
IC: LM3900, 14pin, plus 14-pin socket
Switches: Momentary, push-on(2)

Differential Amplifier circuit

Welcome back to free circuit dot com,today i have true balanced input differential amplifier circuit  , So far we have only used one terminal of the operational amplifier inputs on the amplifier or the “reversal” or “non-inverting” input to a single input signal to the other input connected to the mass increase. But we can also receive signals from both inputs at once to produce another common form of op-amp circuit called a differential amplifier.

   Basically, as we saw in the first tutorial on operational amplifiers, the amplifiers are all “difference amplifier” because of their input configuration. But by connecting a voltage signal proportional to an input signal and another on the other input of the resulting output voltage to the “difference” between the two input signals V1 and V2. Differential amplifier then the difference between two voltages, this type of circuit strengthened doing a subtractor, as opposed to stating amplifier input or the amounts that the input voltages. This type of operational amplifier circuit is commonly known as a differential amplifier configuration is shown below:

Power meter circuit

The power meter(or Watt meter) can accommodate up to 100 watts for a short period and 20 watts continuously.
   You get 20 1K ohm resistors in parallel need, the resistors are 1 watt.

  To calibrate:
   Adjust the 47k for the low performance range against a calibrated power meter, then adjust 470K for the high power range with a power meter calibtated not by changing the 47k with high performance.

VU 220V Circuit

Welcome back to free circuit dot com, What has circuit today ?

For those who like the sound and light system. Today I get to see the VU lamp 220V circuit.
We may see a small LED in the circuit, but we put a sign of coming out with VU and Opto MOC3021M Triac combined to drive the lamp to light.
This circuit is used OptoCoupler Number MOC3021M NL =11 Pcs.
Triac uses a number BT139-600E 11 + signature print and a electronic device.
The stability and make the budget more than $ 15.

For all electronic device list ,you can look at the number on the PCB and part assembly.

you can bring signal from UV IC or LED signal to connect with Opto

Thus as below show device assembly layout.

VU 220 Lamp Device Lay Out

100W amp MOSFET Print Layout

This week we had the same issue of For today, I bring the audio amplifier circuit 100w Mosfet IRFP250N same number.
But I have no schematic to PCB and accessories print layout of a PCB, which can be used immediately.
For a list of devices. I have already mentioned in accessories print layout.
You can supply them all.
The power supply 50Vdc.

We have the PCB thus as picture below.

100W MOSFET PCB

300_watt_MOSFET_real_HI-FI_power_amplifier

300W MOSFET hifi is real genuine passion for excellence hifi My advanced in the past 40 years on the development of sound sonically superior amplifiers to the highest standards, that’s life.

I’m sharing my experiences on the RAS 300 with other fans my passion for perfection.I designed this minimalist amplifier are committed durable, easy to use and offers the same high-fidelity equal to the original source of these partnerships and would only be with other high quality amplifier products recommended.

When I made ​​this amplifier design, my goal is a product that is best suited to provide for the reproduction of complex music and speech signals was capable of creating. Although I pointed out a high electrical properties, the key requirement to achieve a superior sound to hear, vibrant sound stage and excellent sound clarity.We have a componact print layout thus as below.

300_watt_MOSFET_real_HI-FI_power_amplifier_layout

Although the average hearing level is usually less than 10 watts, my approach to an amplifier to reduce with enough reserve capacity to create a design, but bias for class A in the average volume of crossover distortion to extremely low levels .

This is PCB for the project.

300W PCB

There is a capacitor in the signal path, improving the precision of the tonal characteristics of instruments and voices clearly.
The RAS 300 is almost zero phase distortion, far above the audible range, resulting in a perfect overall resolution and color tone.

protection output of amplifiers

The short circuit proof outputs of amplifiers and speakers, throw some interesting elements, such as the isolation of the speakers from the exit of the amplifier, when is a constant tension presented abandoned or if the heatsink temperature rises excessively, the simultaneous and delayed connecting speakers to the amplifier so until we stop them, the familiar sounds of the charge – discharge of capacitors of the supply.

It ¡s is formed by a binary comparator [IC 1], the transistors Q1-2 and preliminary LED D5-6. The supply of the circuit can have a positive stress [point A], especially the food that is on the D3 and R17, the 15V + stabilized.

Electronic Part List

R1-2=27 Kohms
R3=1.4 Kohms  
R4=1 Mohms  
R5-14-17=3.3 Kohms  
R6-7=100 Kohms  
R8=47 Kohms   
R9-11=120 Kohms  
R10=470 Kohms  
R12=15 Kohms  
R13=1.5 Kohms
R15=4.7 Kohms
R16=33 Kohms
R18=1.5 Kohms 5W
C1-2=100uF 63V
C3=470nF 100V MKT
C4-5=47uF 25V
Q1-2-3=BC337
Q4=BC639
D1=1N4148
D2=1N4004
D3=15V 1.5W Zener
D4=1N4002
D5-6=LED
RL1=24V Relay 
RTH=KTY81-122
IC1=LM393

Point B is one of the secondary coil of the main AC-connected transformer. When the power switch of the AC main line, then an AC voltage (secondary coil of the transformer), is shown in section B, is it? D2 from the negative voltage is recovered and deliver them by R9, cut the Q3 of this year and start charging the C4-R10-11. As long as the last time that the charge on the capacitor, the input [+] IC2B comparator is found in small amounts in proportion to the power [-]. The output of IC2B has a low level, so Q4 will remain in the Cutt off and stay ahead of the RL1, which he D6. Only the C4 is charged, the situation changes in the IC1B, RL1 is activated, the speakers to the output of the amplifier, the D6 it out. If it’s interrupted, the process is reversed, and the speaker without breaking pass interference.

If the circuit during the work, the problem of continuing tensions in the output of the amplifier presented in the RL1 and protects the speaker. This is done using the Q1-2. The acoustic signal from the amplifier output, led to point D, the alternative tensions led to the bottom of the C1-2, which is a non-polar capacitor. Continuous voltage that is greater or less than 1.7 V +? 4.8V, immediately activates the Q1 or Q2 of each. With the activation of the transistors of the input level decreases [+] by IC1B, so turn off and RL1. Another section of the protection for us, the heat protection.

This is using the temperature sensor of RTH, the resistance of the PTC (positive temperature factor) has is found and placed back over the heat sink, where the transistors are found. The price to increase with temperature, the potential of the input [-] by IC1A, goes up to the level of input [+], which is determined by the voltage divider R2-3 determined. Once the level of the input [-] are higher than the level of input [+] IC1A exit again at a low level, and the compelling IC2B to change the situation, turn the RL1 and put the D5, which show the thermal protection. The circuit is above the current designation of the thermal protection 70? C. If it? S instability presented in this phase, the effect of RL1 should be changed from the R4, with other smaller prizes. The circuit was in the magazine? Output? 12/95.

Open – Close No Tub. The offset circuit including output fast.
I was stepping into ICs using C instead of applying all the columns in my hi-end audio equipment.  Voltage +-15V.
Small PCB 12.6X6.3 cm. Print zoom – Zoom in itself.

DSL Filter Circuit

When the ADSL and PSTN works on the same line at the same time, a problem the electronics in a normal telephone for high frequency signals ADSL: ADSL signals can be reduced (with high capacity intercom can be resonances in the phone, impedance mismatch ) and ADSL signals can be heard as the sound on some phones (electronic phone demodulates RF signal is out of range voting frequency noise). Just to keep these systems and stop interfering with each other, it is necessary for the two components of the telephone in your home to separate.

This is where the filter / splitter comes in. The ADSL POTS splitter / filter allows you to take full advantage of the frequency 1.1 MHz copper line to take, stopping the ADSL and phone systems interfere with each others.

An ADSL filter is normally a small plastic box with a short cable that connects to your telephone jack and two outputs, one for your ADSL modem and a telephone. Some filters have an exit by calling them. ADSL filter to the frequency band for each of the outlets, telephone or ADSL to select just the right tire and sending in the socket. The output of the phone is not receiving phone frequencies (from DC to 3.4 kHz) and the output is higher and ADSL freuquencies (above 25 kHz).

For good system performance, it is very important that all your other phone equipment is separated from the ADSL signals using a splitter / filter – This equipment includes telephones, answering machines, “normal” modems, etc., etc. .

Continuity Tester Circuit

     Welcome back to Free circuit dot com ,Today we would like to present you with sound tester circuit .

Regarding description will show thus as below .

    The speaker output is not strong, but it is more than adequate for the purpose. I used a loudspeaker small transistor radio with an impedance of 25-80 ohms. Resistance should be reduced to 300 ohms by adding series resistance R8. For example, if your speaker is 58 ohms, then R8 = 242 ohms. Experience is the value of a C1 or C2 to select an oscillation frequency products coinsides mechanical resonance frequency of the speaker in the particular use.

After choosing the right value, which is probably in the range of 10n – 100N, the tone becomes louder and more earpiercing. A D2 “freewheeling” diode is connected through the sensor as the fast switching of sction oscillator circuit can produce a surprisingly large effect of self through the coil and these high voltages could lead to a breach of other transistor damage. Zener diodes do not provide an absolute voltage drop constandt regardless of the current, 0.8 mA on the design of a 8.2 volt diode existing will probably provide only about 8.0 volt drop from the current test selection and marking zener typically 5 mA or more.

  Another possible source of error is the battery, which suggests a nominal 9V gives a new brand can be as much as 9.5 to 9.8 V until slightly rundown and this “surplus” voltage, combined with a “live” znere voltage drop leaves much more than the expected voltage available from the probes. A silicon diode D1 is in series with the Zener voltage of the sensor by creating a new 0.6 volts or more.

  During your final testing and before boxing your circuit, the compound most appropriate A or B is selected for the positive electrode wire. The goal is to complete the oscillator circuit short-circuited probes but to stop an oscillation with the least resistance or the inclusion of a diode (try both directions) between the probes.

   Sensitivity was not because I do not think it’s worth is not necessary and would spoil the simplicity of the circuit. There is no easy way to demonstrate unity against the frame of the offer. Be careful when checking the wiring and the AC line first. Similarly, if checking electronic devices to cover events between Veroboard tracks, as if a crack suspected in a PCB (Printed Circuit Board) to monitor the power first also. Good luck!

Electronic Parts List

R1 = 1K
R2 = 2K2
R3,R4 = 22K
R5 = 2K7
R6,R7 = 56K 9volt Alkaline battery
R8 = *See text suitable loudspeaker
Z1 = 8V2, 1/4 watt
T1 = 2N3905 (PNP)
T2,3,4,5 = 2N3904 (NPN)
D1,D2 = 1N4148
C1,C2 = 22nF housing & probes

Increase current for IC regulator circuit

Although the 78xx series of voltage regulators with different power outputs, you can compare the power generation by stimulating this circuitry. A power transistor is used to provide additional power to the load of the regulator, maintaining a constant voltage.

 Currents up to 650mA is flowing through the regulator, begins above this value and the power transistor to run, which provides additional power to the load. This must be a sufficient heat sink, because it is probably pretty hot.

Suppose you use a 12V regulator, 7812th Input must be a few volts higher to allow for voltage drops. Take 20 volts. Let us also assume that the load to draw 5A.

The power dissipation in the transistor Vce * Ic or (20-12) * 8 = 40 Watt.

There you stay warm in the winter, but you will have a large heatsink with good thermal dissipation needs do. Do you want the output current with a negative regulator, such as increasing the 79xx series, then the circuit is similar, but a kind of power NPN transistor is used instead

Lamp Flasher circuit with MOSFET

Welcome back to free circuit dot com,today we have circuit about control Lamp or call “Lamp Flasher” with MOSFET drive.

The working principle of this circuit is the MOSFET IRF511 and 2, the drive lamp turns on and off.
C1 and C2 with a speed controller works by receiving the voltage at the gate of the MOSFET when the voltage on C turn ON the other would be to drive MOSFET operation.

infrared detector circuit

Welcome again ,Free circuit dot com have the circuit can be used as an infrared beam barrier and a proximity detector.
The circuit uses the very popular Sharp IR module (Vishay module can also be used). NOS pin. circuit is shown in the Sharp and Panasonic modules. For other modules please refer to the relevant datasheets.
The receiver consists of a 555 timer IC working as an oscillator at about 38Khz (also works from 36kHz to 40kHz), which must be configured using the standard 10K. The duty cycle of the IR beam is about 10%. This allows us to more current through the LED, allowing a greater range.
The receiver uses a sharp IR unit. If the IR beam from the transmitter IR drops, the output is activated, which activates the relay and turns off when the beam is blocked. The relay contacts can be used to turn ON / OFF alarm, lights etc. The 10K advance should be adjusted until the receiver detects the IR beam.

The circuit can also be used as a proximity sensor that objects in front of the device detects without obstructing a IR beam. So the LED has the same direction as the IR module and at the same level. The proposed scheme is shown in diagram. The LED should be adequately covered with a reflective material like glass or aluminum plates on the sides to stop the spread of the IR beam to prevent and get a sharp focus the beam.
When there is nothing for them, the IR beam reflected on the unit and therefore the circuit is not activated. When an object comes near the device, the infrared light from the LED reflected from the object on the unit and therefore the circuit is activated.

If there is still a very bad start, use a 1uF or higher capacitor instead of the 0.47uF.

Power supply for amplifier 100W circuit

Wecome back to free circuit dot com,today we have power supply for your audio amplifier with 100 W V-MOSFET.
The proposed power amplifier for 100W V-MOSFET is what appears in the above figure. It has separated supply for the various stages of supply, output stage, stage driver, power amplifier and phase protection. Anyone who wants can remove parts or add a power supply for each channel, separating completely the channels between them. Attention should be given to ground loops. For anyone who does not use the preamp circuit and protection can suppress the corresponding winding.

Out Voltages For Power Supply
+V1=+60V -V1=-60V
+V2=+12V -V2=-12V
+V3=+65V -V3=-65V

Electronic Parts List
C1….4=15000uF 100V
C5-8=2200uF 25V
C15=33nF 630V

IC1=7812
IC2=7912
C6-9=100nF 100V
C7-10=47uF 25V
C11….14=2200uF 100V
BR1=Bridge 250V 25A
BR2=Bridge 250V 3A
BR3=Bridge 250V 3A
T1=220V / 2X43V AC – 250VA
/2X15V AC – 20VA
/2X46V AC – 40VA
S1= 2X2 switch 250V/10A
F1=Fuse 2A slow

Ultrasonic transmitter and recevier

Welcome back to free circuit dot com,today we have the circuit example describes the ultrasonic remote control switch, remote control distance of 10m or more, can be used in a wide range of industrial automation control and home appliances to control. The ultrasonic remote control circuit consists of an ultrasonic transmitter and receiver circuit switching. Ultrasonic transmitter circuit of the S-key, time-base integrated circuit IC 1, transistors V1, V2, R1 ~ R5, potentiometer RP1, diode VD1, VD2, capacitors C1, C2, and the first ultrasonic transmitter consists of B1, as in statements.

   Ultrasonic transmitter circuit ultrasonic receiver circuit comprises an ultrasonic receiver B2, V3 ~ transistors Q5, operational amplifier integrated circuit IC2, relay K, the diode VD3 ~ ~ VD5 and resistors R6 R15, capacitors C3 to C5, potentiometers RP2 and other components, such as shown.

   
Ultrasonic receiver circuit components chosen selection of R1 ~ R15 1/4W carbon film resistors and metal film resistors. RP1 and RP2 use small glass or sealed variable resistors. Use a high frequency ceramic capacitor C1, C2 ~ C5 with monolithic capacitors and polyester capacitors. VD1 ~ VD5 are made Silicon Switching Diode 1N4148. V1, V3 and V4 are all made from silicon NPN transistor S9014, S9015 V2 and V5 with silicon NPN transistor; V6 uses S9013 or C8050 Silicon NPN transistor. Used to give IC1 NE555 5G1555 or if the base integrated circuit IC 2 μA741 use or CA3140, LF351 to amp models such as integrated circuits. Ultrasonic transmitter selection of the head 82 T40 R40 B1 uses ultrasonic receiver. K 9 V DC relay selection, allows the capacity of visual contact can be controlled by electrical current.

Mic mixer circuit

Welcome back to Free circuit dot com again,today we have still audio circuit for your build .
The circuit is a basic 3 input mic mixer circuit with the popular opamp 741 ICs.
Two 741s are used here.U1, U2 are used as preamplifiers.
They produce a gain of around 40 dB to the individual input signals.
The U1 is wired as a summing amplifier to add the signals from three preamplifiers.
IC2 also gives a gain of around 5decibel to the final output signal.
Total gain of the system is around 45 dB.

Electronic Part List

 R1, R2, R3  1K 1/4W Resistor 
R4, R5, R6 10K Logarithmic Pot 
R7  1Meg 1/4W Resistor 
R8, R10  10K 1/4W Resistor 
R9, R11  100K Linear Pot 
C1, C2, C5, C6 0.1uF Ceramic Disc Capacitor 
C3, C4   22nF Ceramic Disc Capacitor 
U1, U2    741 Op Amp 
J1, J2, J3    Input Jacks Of Your Choice 

Note
R9 and R11 control bass and treble, respectively and R1-R3 are level controls.

because the circuit draws such low current, we using  2 X 9V batteries  that can be used for a power supply.

You should be build the mixer in a metal case will cut down on noise.

50W Amplifier Circuit TR 3055 , 2955

Welcome to Free circuit dot com,today we come back with audio power amplifier circuit.

Little pieces of sound equipment, but offline. Voltage only + – 35 more than this would not be sure.
5200 to 1943 using 2955 instead of 3055 with offline without any problems.

Sound reasonable … it is the underlying circuit is really Basic. No help at all. To create one would have to select the device a bit. Because there is no such a key enabling Boost Traping, Constance Current Source, Constance Voltage, Tempurature stable control, ect to which the help of these are important in helping maintain stability of operation of the circuit. Listening to other players in the house.

We have PCB and parts layout and real assembly for you see.

50Watt PCB

50 W Parts Layout

Standby battery circuit

Welcome back to Free circuit dot com ,today i would like to show you with simple circuit that will find many applications as emergency power supply for low power requirements. It consists of a transformer, a rectifier bridge and an electrolytic capacitor followed by a zener, which controls a transistor in serial order. The output is stabilized to + 7.5V. The spare battery 7.5V, in series with D7, floating on the edges of the exit points, ready to take in case of failure (interruption), the main supply. The voltage drop at the edges of D7, will reduce the output voltage from the battery voltage to about 7V. The R3 has a special function during the operation of main power lets a small stream flows to charge the empty data slowly or maintain an already charged battery. It is right that the resistance can be found by dividing the voltage difference between the zener D6 and battery, to secure a stream of leaks, which can amount to some 0,7 milliamps.

Electronic Part List

R1=1K2
R2-3-4=680R
R5=15K
R6=10K
R7-8-9-10=1K
IC1=LM324
D1=5V6 /0.5W Zener
D2-3-4-5=LED
RV1=10K trimmer

battary mornitor circuit

This circuit is used to monitor the battery voltage to display a dual-colored LED status of the battery to. If the LED “green”battery voltage exceeds 11.9 volts. If the yellow LED, battery voltage 11.9 to 11.5 volts. If the LED is “red” If the battery voltage below 11.5 volts. You can of course change the trigger points by the trimmer resistors and / or changing the value of the resistors in the divider.

 A dual op amp is used as a comparator. The green LED on the board, until the voltage exceeds 11.5 volts. The red LED illuminates when the voltage falls below 11.9 volts to the circuit. Therefore, in the 11.9 to 11.5 volts, both LEDs are on, producing a slightly yellow color. When the voltage falls below 11.5 V, the green LED, and now only the red LED flashes to indicate low voltage.

Electronic Parts List

R1=1K2
R2-3-4=680R
R5=15K
R6=10K
R7-8-9-10=1K
IC1=LM324
D1=5V6 /0.5W Zener
D2-3-4-5=LED
RV1=10K trimmer

 Is recommended that multi-shaper for V1 and V2. Muti-trimmer makes it much easier to trigger points to make as a less expensive single-turn trimmer. The trimmer can be completely eliminated if you have access to a range of 1% resistors and has had calculated carefully. You would also want to provide more accurate reference voltage as the common 78L05 regulator.

Photo sensor control relay circuit

Welcome back to Free circuit dot com,a good day, We have new circuit for control relay with photo sensor .

A photo or slightly activated relay normally open relay in the closed circuit / contact with the light. In this circuit, a photodiode is used to sense light. The photodiode has a high resistance in the absence of light strikes. The photodiode is connected to the reverse biased state. The only current flowing through it will be due to minority carriers.
When light falls on it, the minority current carriers in the wake of increasing the diode provides a low resistance. Because the voltage across the diode will not be sufficient to bias transistor Q1 and will be reset. Where there is darkness, the resistance increases photodiode and the voltage across it will be enough to move forward bias the transistor Q1 of the relay ON. The diode D2 is used as a diode to protect transistor switching transients produced relay. In this way, the load on the relay contacts can be switched on and off using light strikes the photodiode.

wireless microphones circuit

DESCRIPTION This circuit contains information about the structure of a small radio transmitter that has a PCB 1.75 “x 2.5″ (45mm x 68 mm) and has a range of about 30 meters or so. The documentation says the circuit, the frequency range is 100-108 MHz, but I found it rather 85-100 MHz. The circuit is (of course) only accepts mono-and one audio line in either a microphone or other source. The input impedance is 1Mohm. The input sensitivity is 5mV and the maximum input signal 10mV. The transmitted signal can be recorded on an FM radio. The circuit can be used for short distance transmission, for example. for wireless microphones. The actual circuit is a “kit”, available at electronics Veleman (USA Distributor Tapto Corp., PO Box 1339, Claremont NH-03 743-US. British traders High-Q Electronics, 382 Edgware Road, London, W2 1EB). The kit number K1771. It is a very good transmitter. I bought the kit and made the track that works very well. I wanted two channels, so I have my own “copy” of PCBs and built the circuit, and in fact my homemade version seems to work better than the original! There is no need to buy the kit actually, because it is a very simple circuit and is the best “home-made channel that I’ve ever seen -. CIRCUIT.GIF is the wiring diagram -. PCBPLAN.GIF shows the PCB layout (see parts) PCBPLAN.GIF is an accurate layout, scanned from the leaflet I have used * in a corner reference mark -… tracks.gif shows to watch on the solder side of the board This is not an accurate layout.. That’s because I really do not plan the route. tracks.gif order, I have a bit of OHP transparencies on the underside of the board, and keeps track with an OHP pen. I then scanned it in. I component leg holes (approximately) have noted with white spots.
Electronic Parts List
D2 1N4148
R1 100K
R2 220K
R3 22R
R4 1K trimmer
R5 1K
R6 56K
R7 1M
R8 1K2
C1 5pF ceramic
C2 6pF ceramic
C3 15pF ceramic
C4 trimmer cap
C5 15pF ceramic
C6 1nF ceramic
C7 100uF electrolytic
C8 4.7uF electrolytic
C9 100pF ceramic
T1 BF244A or BF245A FET
T2 2N3819 FET
T3 BC307/8/9 or BC557/8/9 PNP

Note
that in addition to the components it is a jumper to be installed (marked with a dotted line in PCBPLAN.GIF). The power to use 9-14 V DC, one of the little rectangular 9V batteries in order. Connect with the + and – points on the board. The audio input goes to the places marked “Mike”. The antenna must be connected to the point with “ANT”. The transmitter output impedance is 50 ohms. You can use your own imagination antenna if you want, but I’ve noticed that a foot or so of the ladder is in order.

Preamp PCB with TL072

Welcome back to Free Circuit dot com ,Today,We take the preamplifier circuit with TL072,You can connect with Guitar,DVD player or Iphone.

The preamplifier circuit is shown in the figure has some interesting characteristics that separate “normal” on the assumption that there is such a thing. The circuit was built by an amplifier TL072. This design is simple and offers an excellent range of tones. The structure is designed to obtain a large amount of profit, which is ideal for guitarists who want to fully distorted “fat” to get his job. It is the figure of the circuit.

The preamp uses a dual op amp that any amplification. The single transistor is an emitter follower, and maintains low output impedance after the master volume control. As shown in the figure, with a classical guitar input, it is possible to obtain very large overdrive sound by winding up the volume, then the captain of an appropriate level.

Preamp Assembly layout

The frequency response is deliberately limited to the lower end plate to avoid extreme highs and cut to help reduce noise and the response to the normal requirements for the guitar to a minimum. If you TL072 OP AMP, as shown, you will find that the noise is a problem, especially at high gain with lots of treble boost. I recommend that you use an OPA2134 audio file at a premium, you will find what is perhaps the quietest guitar amp you’ve ever heard. In any gain setting, there is more noise guitar pickup is the prototype circuit noise and carbon resistors preamplifier.

250W MOSFET Amp circuit

Today,We would like to present For you, the power amplifier circuit do now, the price reductions.

be used to listen to the music to play indoor celebration. I begs for to advise this circuit. What I am sure it is of good quality does not play well any expensive stereo system. The circuit, when you consider good.

I think you want to use the appearance of the amplifier circuit with MOSFET MOSFET General, some of the J49 and J50 and K134 or K134.

They are more expensive than necessary. We select a few to use the outcome of the number J162-K1058.

Whose price cuts, much more. Side effects other property otherwise. By canning are usually about 88W for 4 ohm speakers and 55W for 8 ohm speakers.

It can meet the frequency or frequency range 20-50000Hz, and the crazy low THD 20Hz-20kHz 0.05% flow. It is the prominent peak, the high frequency requirements.

Thus as below show you in PCB,Part Layout,Real Assembly.

250W Amplifier MOSFET PCB

250W Amplifier MOSFET Part Layout

Electronic Part List

250W amplifer MOSFET Show case

Voltage low warning circuit

Come again for voltage low warning circuit ,You can apply in your car to check voltage.
The same circuit can be used as an indicator of low voltage alarm when 10 volts Zener diode replaced by a Zener 1N5233B 6.2 volt.

The connection pin 4 of the LM339 and two resistors instead of 10K level sensor.
Connect a 1K resistor in the output of 12 volts (pin 3 of LM339) and a 10K resistor to ground (pin 12 of LM339). Set potentiometer reference voltage 0.5 * Low operating voltage of the street, the output voltage of 5 volts pot , If you travel a circuit with 10 volts. You can reduce the calculation of delay exceeds the threshold of 6.2 volts instead of 10 volts and current, if the index you want to shorten.
Electronic Part
R1, R3 1K 1/4W Resistor
R2 5K Pot
U1 LM339 Op Amp IC
D1 1N5233B Zener Diode
D2 LED
BZ1 Piezo Buzzer

Low voltage warning beeper circuit

Welcome back to Free circuit dot com for today we have the electronic circuit,This circuit is an alarm circuit for low battery status. It gives an audible and visual low voltage 12V battery powered devices. If the battery voltage exceeds the limit set (typically 11V), the circuit is idle. If the battery voltage must be below the setpoint, the LED and the speaker will beep periodically to warn of the impending loss of power punches. The circuit was designed for monitoring solar energy systems, but it can also be useful for automotive and other 12V.

How does it work?
U2 has a market regulated 5V voltage reference. U1 is wired as a comparator compares the voltage fixed 5V regulated voltage at the wiper of VR1, which is proportional to the 12V. If delivery is below the setpoint, the output of U1 goes low, turning on Q1 and food for the beep and the LED.

The acoustic signal consists of U4, a tone generator, and U3, a pulse generator with low duty cycle. The tone can be varied by adjusting R7, the beep rate be changed by adjusting R5. A small amount of hysteresis is provided by R1 and the current through LED1 and the beeper, which separates the points on and off the circuit.

U2 has a market regulated 5V voltage reference. U1 is wired as a comparator compares the voltage fixed 5V regulated voltage at the wiper of VR1, which is proportional to the 12V. If delivery is below the setpoint, the output of U1 goes low, turning on Q1 and food for the beep and the LED.

The acoustic signal consists of U4, a tone generator, and U3, a pulse generator with low duty cycle. The tone can be varied by adjusting R7, the beep rate be changed by adjusting R5. A small amount of hysteresis is provided by R1 and the current through LED1 and the beeper, which separates the points on and off the circuit.

Beeper use low voltage battery
Connect the circuit to the 12V source you wish to attend. Turn on S1, if the battery voltage exceeds the set value, nothing should happen.

If the battery voltage drops below the set value, the LED light and a buzzer will periodically speaker. If the beep is annoying, turn off S1. Make sure the battery fast charge, over discharge, the life of most rechargeable batteries shorten.

remote control tester circuit with sound

This circuit is designed, modulated amplitude (AM) IR light beam demodulation drive a speaker.

This circuit is designed, modulated amplitude (AM) IR light beam demodulation drive a speaker.

infrared remote tester circuit

Today,Free Circuit dot com would like to show you used small infrared remote control tester circuit for controlling the operation of an infrared remote control. 

This is a fairly simple circuit for TV and VCR can be used to test remote controls. The infrared detector module (GP1U52X) (Radio Shack 276-137) provides a 5 volt TTL pulse train corresponding to the digital code to the button of the remote control. In the lower circuit, the module output normally low a signal and a positive going pulse train when a signal is present. Other detector modules that an inverted output is in the upper drawing, which showed type I, but I do not have the part number, I think from a video recorder.

The pulse sequence, the digital codes of special keys is available with information directly from the manufacturer. Since the pulse train occurs, the 4.7uF capacitor charges to approximately 3 volts and the capacitor voltage minus a diode drop appears above the 470-ohm resistor, a collector current of the 2N3904 or 2N3906 about 5 milliamperes. The collector current of the first stage flows into the base of the output transistor (2N3053 or MJE34), which provides about 250 mA in direction.

If the pulse train ends of the capacitor discharged slowly through the bottom of the first transistor stage left, the Christmas tree lights for about 1 second. The little Christmas lights will operate over a wide voltage range, so you can use bulbs from almost any string, but spheres of short strings (35 or less) will probably run longer at least 5 volts.

The circuit can be a small 9-12 volt DC, 250 mA wall transformer or operated higher. It can also be an additional 1000 uF capacitor filter on the DC output if the wall transformer no built-in capacitor. For use with a 9 volt battery, the light bulbs are replaced by a simple LED and 680 Ohm resistor and the output transistors by low signal transistor (2N3904 or 2N3906) can be replaced. The total power is about 25 mA with LED lights, standby and 15 mA when the LED should be.

relay control mosfet circuit

We would like ti show you the circuit is similar to the above, but uses an N-channel MOSFET, as IRF511, 540, 640, etc. instead of the NPN transistor.

Smaller MOSFETs can be used, but I do not know the part numbers. I tested the circuit with a IRF640, IRF511, IRFZ34 and REP50N06. The same circuit has three advantages, but requires only a few parts, always off to the relay and do not need a switch debounce.

In operation, when the relay is deactivated, the 100uF capacitor charge up to 6 volts. When the button is pressed, is on the capacitor 6 volts at the gate MOSFET. The capacitor voltage (and gate voltage) of 6 ms should drop to 3 volts in about 200 to move enough time for relay contacts. At very slow relay, a larger capacity.

With the ratification of the relay, the contacts 12 volts to the resistance produce valid 3.3K 6 volts at the gate, holding that the relay is self-sufficient. The capacitor is then discharged to zero since the relay contact 12 is connected not to the 15K resistor.

When the button is pressed, the capacitor is zero volts to the gate of switching off the relay. There should be no problem making the button again to be the operation of relays, since the gate voltage is only about 1.8 volts when the button is pressed and the MOSFET requires approximately 3.5 volts or more are to start running. But you wait about 1 second or more between pressing a key need, capacitor time to load or unload. Two buttons are displayed, but you could have a number of more parallel to operate the relay from multiple locations

ApeX B500 Amplifier Circuit

Today,We have high power amplifier circuit of ApeX that you know this brand name.

B500, the B250 is based on a number of benefits, and the limiter circuit, schematic and PCB for the same use with B500 and three pairs of + /-65V rails get B250 add.
 You need 500W, 12V to + /-55V DC / DC converter and you can use B500 Auto 2 ohms.
 Director is separate circuit and amplifier can be used to get with every class H amplifier classAB.
 B500 and H900 not step B500 is classAB driver amplifier is Class H and H900 integrited stage driver amplifier.

 If you are found in , we fixed the problem. I was too tired when I measured the track and I have an old 24V fan, and for some reason does not change its speed when the circuit was 24V. Anyway, I’ve now finished for another security, and it works very well (I think). Here are PCB and electronic components layout:

ApeX Audio Amplifier Component Layout and PCB

 For this circuit 625mV. at BD241C at 25 degrees C, gets fans 12V
 If it falls to 440mV, 21V fan gets (I do not know why not 24?) At this point I could barely touch BD241C
 340mV on the protection of LED lights and the relay.
 If the component cools, the relay again.

12 to 24 DC to DC Circuit

Welcome back to Free Circuit dot com,today we have DC to DC converter for your apply to power project or amplifier circuit.

So,We prepare both circuits and component layout too.

DC-DC converter provides a maximum power of about 36 watts at an efficiency of 90%. Besides a modern FET and Schottky diode, this circuit is very well known and cheap parts.

Nevertheless, the specifications are excellent

yield: about 90%
ripple: 10 mV.
max Output current: 1.5 A.
maximum switching frequency: 40 kHz
Input voltage: 12 V.

output voltage: 24 V.

12 to 24 DC-DC-Circuit

12 to 24 DC-DC Circuit 3

regulated The switching element is a quick power FET (T8).
This FET has a relatively high input capacitance and switching on and off by a push / pull phase of two RF transistors (T5/T6). Schottky diode D2 increases even more off-speed, which is crucial here because we strive to achieve the highest possible efficiency.

12V to 24 dc to dc component layout

Stereo phono preamp circuit

We found this circuit on my pc ,i think ,it is Crazy  to post on website this circuit is Stereo Phono Preamplifier (RIAA Filter) circuit Separate phono preamp are nothing new in the audio, but they were mostly to the professional sectors of the industry until the late 80’s limited time in which the compact disc was the dominant force in the audio playback and manufacturers face the law of diminishing returns often opt for the phono EQ section of the amplifier or a cheap IC to cast the function to use in less than ideal sound.

This opens up a whole new market for good quality separate amplifier so seriously still have their vinyl simply not an option, but a buy. But it should also be noted that the purchase of high-quality phono is preamp also an excellent way to can replace your Upgrade Set-up the amplifier without which there is a good way to find a balance in your audio chain to be extremely hot tubes amplifiers allow precise-sounding preamp, and vice versa with one of these wet-sounding English jazz to-amp to play their LP in through the purchase of a valve stage or a sparkling Japanese, etc.

Note that a low power MC cartridges with the help you need either a premap specifically supported, and made sure to get enough and deep enough impedance as a pick, is a low power, or alternatively get one of those fancy MC preamp also. Also be aware that many of the cheaper valve based phono Processors have limited bass response, this is due to the limited available open loop gain and techniques used to correct this often induce phase errors.

automatic turn off relay circuit

Per request the circuit today we have relay circuit.

It is worth noting again that the diagram provides a time delay of about 0.5 seconds for every microfarad in the value of capacitor C1.

This permits delays of up to several minutes. If desired, the delay periods can be made variable by replacing resistor R2 with a fixed and variable resistor in series whose nominal values are approximately equal of the total value of R2 (680K).

Premic IC circuit with LM741

Welcome back to free circuit dot com,We still have post amplifier circuit ,today,We have a pre amplifier circuit for one microphone inputs with IC LM 741.
The 741 is used here. IC1 is used as a preamp. Produce a profit of about 40 decibels to individual input signals. IC1 is wired as an amplifier census to add the signals of three preamps.
 IC1 also a gain of about 5 decibels to final output. Total earnings of the system is about 45 decibels.

Note:
 • Use 15 / 15V DC dual power supply for this circuit.
 • All inputs and outputs to be connected to the ground.
 • The capacitors C1, C2 and C3 must be rated 10V to 30V and other capacitors.
 

General Description

LM 741 IC diagram

 The LM741 series are general purpose operational amplifiers that exceed industry standards like the LM709 function. They are direct, plug-in replacement for the MC1439 709C, LM201, and 748 in most applications. The amplifiers offer many features that make it almost foolproof protection against overloading the input and output, no latch-up when the common-mode range is exceeded, and freedom from oscillations. The LM741C is identical except that the LM741C LM741/LM741A have their guarantee of performance on a 0 ° C to +70 ° C temperature instead of -55 ° C to +125 ° C

wien oscillator 1khz circuit

As is well known that oscillators bridge WIEN, used to generate sine wave signals at low frequencies. Basically consisting of a bass amp, which creates positive and negative feedback. A simplified bridge circuit WIEN seen in Fig. 1. The netting of positive feedback provides the frequency of oscillations. In the simplest case used the same resistors and capacitors, the oscillation frequency is: F = 1/2pRC (1). Increased step down from the panel of negative feedback and is calculated from the relationship: A = RA + RB / RA (2). To maintain the oscillations and synchronos not distorted output signal, enhancing the levels should be slightly higher than the degradation caused the netting of positive feedback. If used the same values ​​of resistors and capacitors in the field of positive feedback, support should be about 3. In practice, the setting of default in payment is made automatically by using a nonlinear element (incandescent lamp, thermistor, or other suitable circuit), which added to the negative feedback loop. In Fig. 2 we see the oscillator circuit. The amplifier has two steps in mating DC. The first step IC1 is an operational amplifier. The second is the output includes two complementary transistors Q1-Q2, a symmetrical arrangement, which allows the oscillator to lead loads greater than 50R. The non-linear element is needed for automatic adjustment of support, formed by the parallel combination of D1-2 and R1. The use of R1 in parallel with these diodes reduces the nonlinearity of the set and keeps a low level of deformation (1-5%), depending on the different parameters that have two channels. The frequency of the oscillations can grow up to 20KIZ without increasing the distortion and correspondingly reduced to low frequencies, provided the coupling is DC. With the materials that give the panel material, the oscillator generates frequency 1KHZ. The frequency can be changed by changing the values ​​of resistors and capacitors, avoiding electrolyte, suffices to keep the relationship R1 = R2 and C1 = C2. The capacity of the capacitor is calculated by F = F 1/2pRC where the output frequency. The current drawn by the circuit is between 10 and 50 mA, when the load is 50R. The supply is + /-9V and can be done by two batteries or by a simple steady power supply. To set the generator must use an oscilloscope, where you’ll see the waveform by adjusting the trimmer TR1, until we see the waveform, with less distortion. If there is an oscilloscope, then just put a 47R resistor in series with the output and a speaker 8W / 0.5W. Change the trimmer TR1 until we hear the oscillation in the loudspeaker, but to go a little longer to adjust trimmer.

Electronic Parts
R1= 1.5Kohm
R2= 12Kohm
R3-4-5= 10Kohm
R6= 2.7Kohm
R7-8= 10ohm
TR1= 10Kohm Trimmer
Q1= BC550C
Q2= BC560C
C1-2= 10nF 100V polyester
C-3= 100nF 100V
All R is metal film 1%
D1-4= 1N4148
IC1= TL071-NE5534-LM741

bipolar 300 w circuit

Note that the specification for this amplifier has been extended and now for high continuous power into 4 ohms, but you have to go to the extreme with the heat sink (fan is highly recommended). It was originally designed for “light” intermittent operation, the binding of a subwoofer system (- see project page for information on this route as the ELF-principle) determined. Where continuous high power is needed, there are 4 output transistors recommended wired the same way as Q9, Q10, Q11 and Q12 and the use of 0.33 Ohm emitter resistors.

Output power into 8 ohms is usually more than 150W (250W for ± 70 V supply), and it can be without full power transistors used in an 8 ohm all day, every day. The additional transistors are required only if you want to the same max power at 4 ohms! Think not even asked about the use of supplies of ± 70 V, and bothered me if it’s okay – it’s not!

The circuit is shown in Figure 1, and it is a fairly conventional design. The connections are for internal SIM card (published elsewhere on the project pages) is provided for filtering and RF protection (R1, C2) is provided. The entrance is through a bipolar 4.7uF cap, as this much capacity in a small format. Because the impedance is little or no degradation of the audio clear. A polyester cap can be used if you prefer to be – give 1uF with nominal impedance of 22k, a-3dB frequency of 7.2Hz, which is quite low enough for a sub-group.

300W bipolar amplifier PCB

The first stage is a conventional long-tail pair and uses a current sink (Q1) in the emitter circuit. I decided to use as a current sink to ensure that the amplifier would quickly on demand (and distance) to stabilize the power to convert eliminate the dreaded “blow”. The amplifier is actually quite stable at operating conditions with as little as + / -5 volts! Also note that connections for the SIM card (Sound Monitor Special), representing an average better than conventional clipping ads. See the project pages for more information about creating a SIM circuit. If you think you do not need the SIM, let R4 and R15.

The class-A driver is again conventional, and uses a stabilization Miller cap. This component requires either a 500V or a ceramic device for polystyrene are the best linearity. The tax collector is the bootstrap principle rather than an active current sink, because it is cheaper and very reliable (except, I love the bootstrap principle is

 All three driver transistors (Q4, 5 & 6) must be on a heat sink, and D2 and D3 should be a good thermal contact with the driver heatsink. Otherwise, the result is thermal instability and the amplifier will fail. For some reason seems to be the last statement for some people to cause confusion – see the picture below and you will see the small heatsink, 3-driver transistors and a white “blob” (only for the electrolytic capacitor on the left) that the two diodes to the heat sink with thermal paste down.

C11 is not on this list, so do not bother looking for it. It was “lost” if the schedule was created, and I did not notice until someone asked me where and what it should be. Sorry.

It is in the final stage that the performance of the amplifier is revealed. The most important result is related to many of my designs, but with a higher level than normal for the “sender” resistors (R16, R17). The voltage across these resistors is then the current basis for the main output devices are used in full Class-B are available. In some ways this is a “bad man” version of the famous Quad current dumping circuit but without the refinements, and in principle is the same as in the equally famous Crown DC300A power amps used.

Although I have shown and MJL4281A MJL4302A output transistors because they are new, most manufacturers feel that they are not as readily available as they should. The alternatives are MJL3281 / or MJL1302 MJL21193 / MJL21194.

Note: It is not possible to recommend a Toshiba transistors, since they forged the most of all. The 2SA1302 and 2SC3281 are now obsolete – if you find them, they are almost certainly wrong, because Toshiba does not have this equipment since about 1999 ~ 2000th
Use a standard green LED. Do not use high brightness and other colors because they have a slightly different forward voltage, and this will drop the current functioning of change – this may be a miniature type, if desired. The resistors are all 1/4W (preferably metal foil), except for R10, R11 and R22, the 1W carbon film. All low value resistors (3.3 ohms and 0.33 ohms) are 5W WIREWOUND types.

Because this amplifier operates in “pure” class B (something like a contradiction in terms, I think), the high frequency distortion is relatively high, and may not be suitable for high-performance hi-fi. is the low end of the spectrum, much negative feedback and distortion is actually pretty good, at about 0.04 kHz to% 1. My first tests and reports of others show that there are no audible artifacts at high frequencies, but remains the recommendation.

Power amp 400W IRFP448 Circuit

Amplifier circuit today,We would like to show you for the MOSFET 400 watt amplifier is amplifier on my kW shares the same circuit and basic PCB layout.
  The only real difference is the number of output devices to the device.
  We have using The IRFP448 design while the MOSFET amplifier 14 O / P devices.
  These amplifiers can be used for virtually any application that requires high performance, low use Noise, distortion and excellent sound quality. Examples would be subwoofer amplifier should FOH stage
  Amplifiers, surround a canal a very powerful sound amplifier, etc.
  The 400W MOSFET-amplifier has four key stages of amplification. We are looking to start any   Phase appropriate detail.

The bias and buffer stage
  As the name suggests All Q ,C and ZD the Bias and buffer phases. Its main goal is to provide a stable MOSFET Gates  and offset voltage and the voltage buffer amplifier stage of the High Resource capacity. What would have without the phase response and the effect
  Slew rate is indeed very bad. The flip side of the coin is not the extra step
  Introduction of an additional dominant pole in the amplifier feedback loop.

400W MOSFET PCB

Power amp 400W IRFP448 PCB

and We have the electronic components layout thus as below

Power amp 400W IRFP448 PCB Layout

We have to continue in power circuit PCB and components layout

Power for Amplifier 400W IRFP448 Mesfet PCB

400W Power IRFP448 Mesfet PCB Layout

  
  The final stage of the Current Gain Stage
  Also to what the name suggests this stage converts the voltage developed in the VAS
  and provides all the amps required to drive at 8 or 4 ohms. 2-ohm loads are possible
  for several minutes at a time. In fact, I have tested more than 1600 1kW amplifier
  Watts RMS at 2 ohms. But that would not be recommended as a long-term exposure at all.
  If it is higher than the figures of the STI-amp.
  Power to the AV amplifier 800
  The components of the power for this amplifier are as follows, and are favored
  A channel or a power module alone.
  1 toroidal transformer with a rating of 1kVA. Primary windings are made to fit

1KW_MOSFET_AMPLIFIER CIRCUIT

Welcome to free circuit dot com ,Today i’m still present the audio amplifier circuit ,I like the supper amplifier .

So,I would like to show you the 1000Watts  MOSFET amplifier circuit for your build sound system.

Click the picture left side to open the Circuit in PDF file.

I include full schemaatic chart and film; pattern of the 1000-watt amplifier and a step by step instructions for setting the construction of the amplifier is a true full 1000 watts per channel.

 I have been building and playing very well goood can drive a 18 Bring with inch subwoofer dual magnet high performance at UA smooth clear and crisp sound that I used for outdoor event and mobile services when building you will, said this amp I can only contact me gave my email Mail on how to get this project … I assure you his powerful …. You could, but I have to return it a full program of 20 band equalizer can be difficult to find on the net …

6 band graphic equaliser circuit using 741 op amp

Welcome back to Free circuit dot com,today we have the audio circuit for improve your sound system,this circuit is 6 Band Graphic Equaliser ,you can adjust sound in low ,mid and high which circuit used IC 741 Op-Amp.

Audible Frequency spectrum is treated in six bands: 50Hz, 160Hz, 500Hz, 1.6kHz, 5kHz, 16kHz. All potentiometers are linear type of 100k. The circuit offers a lot of cut / boost for normal use.

We have show you the parts list thus as below .

ELECTRONIC PARTS LIST
R1, R2, R3, R4, R5, R6 27kΩ
R7 470kΩ
R8 330kΩ
R9 100kΩ
R10 4.7kΩ
R11 4.7kΩ
VR1, VR2, VR3, VR4, VR5, VR6 100kΩ
C1 100n (104)
C2 33n (333)
C3 10n (103)
C4 3.3n (332)
C5 1n (102)
C6 300pF (301)
C7 100µF 16V
C8 4.7µF 16V
C9 47µF 16V
IC1 741 Op amp 

Power for the circuit of the amp / preamp itself derived. The wide range of power supply (6V-15V) makes the circuit very versatile. The power consumption is negligible.