This is a variable power supply controlled with PIC microcontroller. There is LCD display in this circuit which will show the actual value of power supply output. This power supply use push on switch to adjust the output voltage and current value.

Schematic Diagram:

Component List:
C1 = 2000uF per AMP, 40V (adjust capacity to power supply amps)
C2,C3,C12,C15,C18,C21 = 0.1uF CER
C4 = 0.01uF CER
C5A,C5B,C5C,C5D = 0.01uF CER
C6,C7 = 0.05uF CER
C8 = Not used
C9,C11,C19,C20 = 1uF CER
C10 = 470uF 15V EL RADIAL
C13 = 4.7µF 50V EL RADIAL
C14 = 0.001uF CER
C16,C17 = 22pF CER

This is the curcuit application of power amplifier IC LM4756. The IC have the capability to deliver dual output channel at 7W for each channel. Like the other audio amplifier circuits, this circuit just need a few external components to work.

Circuit application:

PCB design:

This is another power amplifier circuit with power IC KA series. This amplifier delivers dual power output (stereo) at 1.2W for each channel.

The KA2214 is a monolithic integrated dual audio power amplifier in a 14-pin plastic dual in line package. It is designed portable audio sets.

This is a stereo power amplifier based on Samsung IC KA2211. With single chip, this circuit will deliver up to 5.8W on each output channel.

KA2211 is a dual audio power amplifier for consumer application. It is designed for high power, low dissipation dan low noise. Is also contains various of protectors and suitable for car audio power amplifier with high performance.

This is a Hi-Fi power amplifier circuit build based on single power amplifier IC TDA2040. The single TDA2040 has able to deliver 20W power output. The bridge amplifier which consist of double TDA2040 can deliver 30W power output (8 ohm loudspeaker).

About power amplifier IC TDA2040:

The TDA2040 is a monolithic integrated circuit in Pentawatt  package, intended for use as an audio class AB amplifier. Typically it provides 22W output power (d = 0.5%) at Vs = 32V/4W . The TDA2040 provides high output current and has very low harmonic and cross-over distortion. Further the device incorporates a patented short circuit protection system comprising an arrangement for automatically limiting the dissipated power so as to keep the working point of the output transistors within their safe operating area. A thermal shut-down system is also included.