Power circuit diagrams

Variable PSU 3-15v

A variable power supply with adjustable voltage and current outputs made with the L200 regulator.

Variable Power Supply Using Fixed Regulator

This is a similar power supply that I used to power my FM Transmitter. After suffering long problems with mains hum, this design using a pi filtered C-L-C approach. This circuit offers excellent ripple rejection.

Multiple Output DC Converter

A DC converter circuit taking one single DC input and converting to parallel multiple DC outputs.

Logic PSU with Overvoltage Protection

A simple 5 Volt regulated PSU featuring overvoltage protection.


Following a hunch, the author discovered (or re-discovered?) that all plants carry an electric charge relative to the ground. This charge is more or less constant regardless of the size of the plant - a kind of "background voltage" in nature.

Power Failure Alarm

This is a very basic alarm designed to let you know when the electricity supply fails. The alarm is powered from a battery which uses no current consumption at all in standby, a battery should therefore last its full shelf life.

The Output Adjustable Flyback Converter

A high voltage step-up DC power supply using adjustable flyback conversion.

1.5 to 37 Volt 30 Amp Power Supply

A modification to the 12V 30 Amp power supply. This version uses an LM317 to provide a variable 1.5 to 37 Volt regulated output with currents up to 30 Amps. Max has built his power supply into an old computer case and can be seen on YouTube under Project Icarus.

Dual Regulated PSU

In this circuit, the 7815 regulatates the positive supply, and the 7915 regulates the negative supply.

Fast Electronic Fuse

A fast electronic fuse designed to operate on 230V AC with an adjustable trip current.

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