13.8 Volt 20 A Transformerless Power Supply

Do you need high current power supply without heavy and expensive transformer? Then, this circuit would be great choice for you.

This 13.8 Volt 20 A regulated transformerless power supply. 20A transformer is very-very expensive, large in size and very heavy in weight.

This power supply capable in delivers around 20Amps at 13.8V. For lower currents, a separate current limiting output, capable of 15ma up to a total of 20A has been added. Let us see what we have got here. The power transformer should be capable to deliver at least 25A at 17.5 to 20V. The lower the voltage, the lower power dissipation. The rectified current will be ironed by the C1, whose capacity should not be less than 40.000uF, (a golden rule of around 2000uF/A), but we recommend up to 50.000uF. This capacity can be built up by several smaller capacitors in parallel. The base of this design is a simple 12V regulator IC 7812.

More explanation about this circuit, please visit this page

circuit schematic

View Comments

Recent Posts

Switched ON Bike Lamp

Do you have a bicycle..? why don't try to build this circuit..?. Powered using battery…

54 years ago

3A Switching Power Supply Regulator

This is the circuit diagram of 3A switching power supply regulator: Simple and cheap, the…

54 years ago

Remote Control Tester

Here is the remote control tester circuit. This circuit is really a simple and easy…

54 years ago

Current Output Multiplier for 78xx Regulator

This is the circuit diagram of current output multiplier designed for regulator IC LM78xx. By…

54 years ago

4 Transistor FM Tracking Transmitter

The following diagram is the FM tracking transmitter based on 4 transistors. No additional notes…

54 years ago

White Line Follower

This is the circuit diagram of white line follower toy. The actuator of the toy…

54 years ago