Newest circuit diagrams

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.

Multi Wire Cable Tester

A multi wire cable tester with a separate LED for each wire. Will show open circuits, short circuits, reversals, earth faults, continuity and all with four IC's. Designed initially for my intercom, but can be used with alarm wiring, CAT 5 cables and more.

Cellular Phone calling Detector

Flashes a LED when detecting an incoming call Powered by one 1.5V cell

Self-powered Door-bell Watcher

Detects if the door-bell has rung in your absence Also suitable for different electric appliances

Vinyl Pre-Amplifier

For those who might wish to 'save' to their computer hard-drive a digital copy of their own vinyl record collection, I have redrawn my 1975 vinyl pre-amplifier circuit. It remains capable of optimising disc playback and offers features still not repeated today.

Unregulated PSU

A basic full wave rectified power supply

Dark Activated Switch

This circuit will activate a relay when light falls to a preset level. Light level can be adjusted with VR1 and the relay contacts may be used to operate an external light or buzzer.

Electronic Night Light

This circuit for an electronic night light was submitted by Adam from Canada.

Door Alarm

Hangs up on the door-handle. Beeps when someone touches the door-handle from outside.

Variable DC Power Supply