170W Audio Power Amplifier.

Download this schematic diagram.

Download part list component.

Datasheet semiconductor component.

1. NE5534

2. MJE350

3. MJE340

4. BD139

5. BC546B

6. BC556B

7. MJE15030

8. MJE15031

9. MJE15003

10. MJE15004

11. BAT85

12. IN4004

13. BY254

The circuit is being powered by two 15V power supply for each channel, that is regulated by the combination of resistors R7-9 and Zener diodes D1-2. The frequency bandwidth is limited to a specific value due to the presence of low pass filter from R2 & C2 and high pass filter from R3 & C1. The total feedback of the circuit is concentrated on the positive non-inverting input of the IC1 that functions as differential amplifier. The node of R4-5 is applied with the feedback voltage from the output through R6. The current regulated by R10 & R14 across Q1-2 is 10mA as they operate in class A while in class AB, the power transistors Q8-11 operate in the output with a regulated constant current of 100mA each power transistor, done by trimmer TR1 and Q3. This will match the voltage drop at 27mV, higher than the provided voltage of R25-28.

A heatsink with sufficient dimension to provide cooling is placed above Q1-2-3-6-7 to maintain the possible thermic stability while the protection from reverse voltages from the load is performed by diodes D9-10.Additional fan can also be employed to suppress high temperature for efficient operation. The stability during high frequencies is sustained by the Zobel network consisting of R29 & C18. Due to capacitive load, the amplifier output is protected by a 1mm diameter 15-coil inductor L1 with R30 for square pulses passage.

Each power amplifier that is created will correspond to a transformer to handle large capacitors and provide proportional power. The transformer input is connected to the AC line which can incorporate delay circuit for protection from excessive supply. The cables that would carry the current to the amplifier should be appropriate enough.

1000 W Power Amplifier Schematic Diagram.

Download this schematic diagram.




Datasheet semiconductor component download.

1. BC546
2. BD681
3. MJE350
4. MJE340
5. 2SC5200
6. 2SA1943
7. 2SA1494
8. 2SC3858

The assemble cables for DC power supply and output transistors must be large, use size 1.5-3mm for large current passed. The supply used transformer with 20A/45Ct and at least 4x10000uf/80 volt capasitor. this circuit is able to supply power 10000watt therefore the power transistor will be very hot, give good cooling fan on the power transisitor

Transitor alternative to replacement of the 2SA1494 is 2SA1216 From SANKEN. The transistor has a 200-350 watt power dissipation of each pair so that for long-term operation of more durable. Keep in mind, usually sold a pair of power transistors with its complement, so you can not buy 2SC2922 alone without 2SA1216 or 2SA1494 without 2SC3858.

15 Watt Mini Amplifier

A 15 watt amplifier made using discrete components. Sergio designed this circuit for his Electronics Level II course.






Download this schematic diagram.






Download list datasheet semiconductor component. (PDF Format)

1. 2N3904
2. 2N2907A
3. 2N3906
4. IN4002


Notes:
This amplifier uses a dual 20 Volt power supply and delivers 15 watts RMS into an 8 ohm load. Q1 operates in common emitter, the input signal being passed to the bias chain consisting of Q8, Q9, D6, D13 and D14. Q8 and Q9 provide a constant current through the bias chain to minimize distortion, the output stage formed by a discrete darlington pair (Q2,Q4) and (Q7,Q11). The last two transistors are power Transitors, specifically the 2N3055 and MJ2955. The 7.02K resistor, R16 was made using a series combination of a 4.7K, 680 Ohms, and two 820 Ohms. The 1.1K resistor, R3 was made using a 100 Ohms and a 1K resistor. You can use this circuit with any walkman or CD player since it is designed to take a standard 500mv RMS signal.

http://www.zen22142.zen.co.uk/

Capacitor Explanation

A capacitor is a passive electrical component that can store energy in the electric field between a pair of conductors (called "plates"). The process of storing energy in the capacitor is known as "charging", and involves electric charges of equal magnitude, but opposite polarity, building up on each plate. A capacitor's ability to store charge is measured by its capacitance, in units of farads.

Capacitors are often used in electric and electronic circuits as energy-storage devices. They can also be used to differentiate between high-frequency and low-frequency signals. This property makes them useful in electronic filters. Practical capacitors have series resistance, internal leakage of charge, series inductance and other non-ideal properties not found in a theoretical, ideal, capacitor.

The capacitor is used in almost every electronic circuit. It is a very important component and it does many different things, depending on where it is placed.

A capacitor is basically a device that stores a charge of electricity.
It has two or more plates that are separated by air or a non conducting medium such as plastic.

A basic capacitor is shown in the diagram below with the corresponding circuit symbol.

Capacitors can be large or small and the size is the result of the value of the capacitor as well as the voltage it is capable of withstanding.

There is a lot to learn about capacitors and we will only be discussing the very basics.
There are many types of capacitors, here are 5 of the most common types:

AIR - such as a tuning capacitor in a radio.

GREENCAP - a polyester capacitor.

CERAMIC - a ceramic insulating material that produces a very compact
capacitor

MONOBLOCK - also called monolithic - a multi-cceramic capacitor

ELECTROLYTIC - aluminium plates with a moist insulating medium. This type of capacitor has a very high capacitance in a small space.

The diagram below shows a single-ended electrolytic, suitable for mounting on a printed circuit board and the symbol.

The unit for capacitance is the FARAD. But one Farad is an enormous value and we don't use values this large in electronics. The value we use is the micro-farad. A microfarad is one-millionth of a farad.

For some circuits we need capacitors of more than 1 microfarad capacitance and for others we need less than 1 microfarad.

For a power supply we need electrolytics of 10 microfarad, 100 microfarad, 1,000 microfarad and even 10,000 microfarad. The letter to signify microfarad is "uF" or simply "u". Thus 1microfarad is 1u, 10 microfarad is 10u etc.

For audio work we need smaller values such as .1microfarad and .01 microfarad.
In electronics, we try and avoid using the decimal point as it can be rubbed off components and omitted from photocopies of circuit diagrams.

To get around this we use sub-multiples and the sub-multiple of microfarad is nanofarad.

1,000 nanofarad = 1 microfarad.
Thus .1u = 100 nanofarad.
The letter to represent nanofarad is "n".
Thus .01u = 10n

For radio frequency work, even smaller values of capacitance are needed.

The nanofarad is divided into 1,000 parts called picofarad. Thus 1,000 picofarad = 1nanofarad.

The picofarad is written pF or simply "p."
Thus 1,000p = 1n.

Some capacitors are physically very small and there is very little space to write the component value. To get around this, manufacturers have produced a numbering system using 3 digits.

It is based on picofarads. A 100 picofarad capacitor is written as 101, A 1,000 picofarad capacitor is written 102, A 10 nanofarad capacitor is written 103 and 100 nanofarads is written 104. The third digit represents the number of zero's.

For example: 1n = 1,000p = 102.
10n = 10,000 = 103
100n = 100,000 = 104