Power circuit diagrams

Overvoltage Protection for the LM317

This is an add-on Over Voltage Circuit for the LM317 Regulator Circuit submitted by Matthew Hewson.

Digital Remote Thermometer

Remote sensor sends data via mains supply Temperature range: 00.0 to 99.9 °C

Solar Battery Charger

A solar battery charger that uses a shunt regulator to prevent overcharging. Circuit uses a 12V solar battery, but can be adapted for other voltages.

Transformerless Power Supply

I have had several requests for a power supply project without using a power supply. This can save the expense of buying a transformer, but presents potentially lethal voltages at the output terminals.Under no circumstances should a beginner attempt to build such a project.

Unregulated PSU

A basic full wave rectified power supply

Variable DC Power Supply

Self-powered Fast Battery-Tester

Tests 1.5 to 15 Volt cells Two-LED display, no power supply required

Supply Voltage Indicator

A novel supply voltage monitor which uses a LED to show the status of a power supply.

Regulated 12 Volt Supply

A basic regulated 12 Volt power supply

L200 Power Supply

Power supply with variable voltage and fixed current regulation made using the ubiquitous L200C regulator.