5,000W ultra-light, high-power amplifier, without switching-mode power supply

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1. MPSA.42

2. MPSA.92

3. MPSW.42

4. MPSW.92

5. 2SA1302

6. 2SC3281

7. MJL21193

8.MJL21194

9. LM7815

10. LM7915

This circuit is of an 2x 2,500W RMS stereo amplifier, super-light and without switching-mode power supply. The circuit just shows a channel, and the power supply that it assists to the two channels. The audio circuit should be duplicated, but the power supply assists to the two channels without problems.

A special care should be destined to the insulating transformer of the audio line, that should be of audio-high-quality, of the type used in microphone pre amps input line. The whole group (2 channels) of 5,000W RMS it should not weigh more than 32 lbs, already inside of an appropriate metallic box.

WARNING:

This circuit is exclusively for amateur use. It contains not-isolated parts of the electric AC net and it can be very dangerous. The connections for the speakers are not isolated of the domestic AC net and it requests extra care. This procedure seeks to substitute a conventional power supply with great weight and cost reduction, without necessarily to use a switching-mode power supply.

This procedure cannot be allowed in some countries for commercial-use. The author doesn't have any responsibility for the form as that circuit it will be applied.

LM2577 5V to 12V DC Converter step up Voltage Regulator

DC to DC step up voltage regulator. Wide input voltage 3.5Vdc to 40Vdc. This is Circuit DC to DC converter step up vol



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1. LM2577
2. IN5821

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Injector Pulse Width Monitor with LM324 ,LM3914

The schematic for the pulse width monitor. The heart of the circuit is the transistor current source which charges cap C10 to form an integrator. The theory is that the cap is charged and the voltage across it increases linearly for the amount of time that the injector is energized. As the injector is switched off the voltage in C10 is stored in cap C9 and then C10 is reset to 0 volts to get ready for the next cycle. The output of the circuit is the voltage across cap C9, this voltage is fed directly into U3 the bar graph chip to be displayed as a value between 1-10 on the LEDs. Potentiometer R31 sets the charge rate on C10 and basically sets the max injector on time that can be displayed.

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1. LM324

2. LM3914

3. CD4058

4. LM7805

5. MN3206

6. MN3906

7. 2N2222

8. IN214

9. IN5233

Injector Pulse Width Monitor with LM324 ,LM3914 - [Link]

Temperature Monitor with IC LM741 or LM301

Using a thermistor in the position shown makes a heat activated sensor. A change in temperature will alter the output of the opamp and energize the relay and light the LED. Swapping the position of the thermistor and 47k resistor makes a cold or frost alarm.

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1. LM741

2. LM301

3. BC182B

Temperature Monitor with IC LM741 or LM301 - [Link]

2N3055 Simple inverter 5W

This simple inverter. The main aim of this circuit is to provide a suitable supply for all kind of low power battery chargers that normally connect to the mains such as mobile phones, electric shavers, etc, even an electronic neon light rated at 5W was successfully connected. Only easily obtainable components are used.


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1. 2N3055

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Nagative voltage generation using 555 timer

This 555 timer based PWM controller features almost 0..100% pulse width regulation using R1, while keeping the oscillator frequency relatively stable. The frequency is dependent on values of R1 and C1, values shown will give a frequency range from about 170 to 200 Hz. Any 555 chip will do, CMOS is fine as well. Diodes are not critical, I used 1N4148. Total cost of parts is about $2. As the whole thing is quite trivial, it’s very easy to build on prototyping board like I did.

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1. NE555

2. BD140

PWM Speed Motor Controller By IC 555-Electronic control circuit - [Link]

Power Amplifier with STK40xx Series Module

The series STK40xx is power amplifiers in completed form in a nutshell. They are characterized by the very good quality of sound and their low price. It is easy we make a power amplifier using only few external components. The STKxxxx amplifiers, for them we will find in enough eponymous stereo amplifiers , but also in enough activety loudspeakers. They do not need a lot of special knowledge of manufacture, only that attention in pins, in order to they do not break, and one good power supply. Details for the various types of series, voltage of work and the output power, see the Table A

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1. STK 40XX

Power Amplifier with STK40xx Series Module - [Link]

LM317T Voltage Regulator with Pass Transistor

The LM317T output current can be increased by using an additional power transistor to share a portion of the total current. The amount of current sharing is established with a resistor placed in series with the 317 input and a resistor placed in series with the emitter of the pass transistor.




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1. 2N2955
2. LM317A
3. IN4002

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Line Driver

Description:

A stereo line driver for feeding long cables or buffering an audio source.




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1. BC109C

Notes

This preamplifier has a low output impedance, and is designed to drive long cables, allowing you to listen to a remote music source without having to buy expensive screened cables. The very low output impedance of around 16 ohms at 1KHz, makes it possible to use ordinary bell wire,loudspeaker or alarm cable for connection. The preamplifier must be placed near the remote music source, for example a CD player. The cable is then run to a remote location where you want to listen. The output of this preamp has a gain of slightly less than one, so an external amplifier must be used to drive loudspeakers.

Buffer Amplifier

Description:

A hifi preamplifier designed to convert high output impedance amplifiers to 600 ohm outputs.










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List datasheet semiconductor parts. (PDF Format)

1. BC547C
2. BC557C
3. 2SA1358
4. 2SC3421

TDA2030 8w Amplifier

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1. TDA2030
2. IN4001


Notes

Although the TDA2030 is capable of delivering 20 watts of audio power, I deliberately reduced the output to about 8 watts to drive 10 watt speakers. This is more than adequate for a smaller room. Input sensitivity is 200mV. Higher input levels naturally will give greater output, but no distortion should be heard. The gain is set by the 47k and 1.5k resistors. The TDA2030 IC is affordable and makes a good replacement amplifier for low to medium audio power systems. Incidentally, it is speaker efficiency that determines how "loud" the sound is. Speaker efficiency or sound pressure level (SPL) is usually quoted in dB/meter. A speaker with an SPL of 97dB/m will sound louder than a speaker with an SPL of 95dB/m.