Newest circuit diagrams

AC Switch

An AC triggered switch for low frequency signals.

Cricket Chirping Generator

Funny gadget for props and jokes. 5 - 12V Battery operation

Metronome Circuit

A metronome circuit based on a simple astable. The output sound is distorted to emphasize the pulses.

Magnetic-Radiation Remote-Control

Short-range 35KHz operation, single-channel units. Simple circuitry, no outer antennas required

Radio Wave Alarm

This simple circuit is sure to have the police beating a path to your door- however, it has the added advantage of alerting you to their presence even before their footsteps fall on the doormat.

Plant Watering Watcher

A flashing LED signals the necessity to water a plant Very low current consumption - 3V powered circuit

Water Level Alarm

A circuit that offers visual indication of fluid level in a vessel, with a switchable audible alarm. Example uses would be to monitor the level of water in a bath or cold storage tank.

Audio Voice-Over Circuit

This is a circuit where a microphone and preamp circuit (voice circuit) have priority over any other audio signal. You can think of this as a one way intercom, if the main amplifier is used for listening to music, then when the push to talk switch is pressed, the amplifier is switched to the voice signal.

Energy Saving Soldering Station

This circuit appears in the test circuit section because the soldering iron is one of the most used service aids. This circuit, will not only save power when the soldering iron in not in use, but will also preserve the tip life.

Simple Field Strength Meter

This Field Strength Meter is simple and also quite sensitive. It uses an ordinary digital voltmeter to measure RF signal strength up to a few hundred MHz.