Power circuit diagrams

Power Fail Alert

In this circuit an electricity supply (domestic or industrial) is continually monitored. Should the supply be interrupted then an alarm will sound for the duration of the interruption. It has battery backup and overcharge protection.

230Vac Lamp Toggle Switch

Compact, transformerless circuitry. No relays employed

LM317 Voltage Regulator

The voltage regulator is an LM317T, and should accept up to about 14 volts without problems. It can handle up to 1 amp.

Power Zener Circuit

In this circuit a zener diode is "amplified" by a set of power transistors. The transistors substantially increase the current and power to the load.