Power circuit diagrams

Fuse Monitor Indicator

The simplicity of this circuit uses just two components, but with just one resistor and an LED this circuit gives visual indication of when a fuse has blown.

AC Current Monitor

Senses high current-flow into power cables No wire-cutting, three versions available

Current Limiting Power Supply

This is a 1-amp variable-voltage PSU. It adjusts from about 3v to 24v: and has the added feature that you can limit the maximum output current. This is invaluable when (for example) you power-up a project for the first time or soak-test a piece of equipment.

Flashing-LED Battery-status Indicator

Signals when an on-circuit battery is exhausted. 5V to 12V operating voltage.

Battery Status Indicator

There are many circuits available on the net, for indicating battery status.

Universal DC-DC Convertor

This circuit will generate a smaller DC output voltage from a larger DC input voltage.It is quick and simple to make and by changing the value of the zener diode, the circuit can be universally adapted to provide other output voltages.The circuit and all diagrams represent a DC convertor with 12V battery input and 9Volt DC output.

1.3 Volt Power Source

This is a replacement power source for 1.3V mercury cells or other small batteries. It has many uses and I use this circuit in my computer to power a front panel multi adapter which has a digital thermometer.

Universal PSU

A Universal Power supply based on the L200 regulator, which includes an outboard pass transistor to boost output currents up to 4 amps.

Increasing Regulator Current

An outboard pass transistor used to increase the current output of a voltage regulator IC.

Adjustable Power Supply with Charger Output

This power supply has adjustable and charger output. The charger circuit can be use for cellular phone. The adjustable output serves as multipurpose power supply. It can handle a 1 ampere current. The 317 must have a heat sink.