Newest circuit diagrams

Motorcycle Alarm No.8

This is a simple motorcycle alarm - with a time limit on the siren. While the thief continues to move the bike - and the normally-open trigger switch continues to open and close - the siren will continue to sound. When the bike stops moving - the siren will cut-off.

Combinational Conjuring Trick

The simple circuit of Fig.1 emulates a similar conjuring trick which sells for hundreds of Pounds. The trick seems to do the almost-impossible from an electronic point of view, let alone from the point of view of common sense.

Schmitt Trigger

This circuit uses a single op-amp and the output is triggered by two different voltage levels.

Electronic Canary

An electronic version of a chirping canary. May be used as an alarm, a sound effects generator or perhaps a replacement doorbell.

Displacement Alarm

Warns if an object is moved, Small gadget - 9V Battery supply

Multiple Output DC Converter

A DC converter circuit taking one single DC input and converting to parallel multiple DC outputs.

Laser Communication System

This is a simple Laser communication system. It can transmit and receive signal from any audio device.

Logic PSU with Overvoltage Protection

A simple 5 Volt regulated PSU featuring overvoltage protection.

741 Astable Timer

An astable timing circuit made from the ubiquitous 741 op-amp.


Following a hunch, the author discovered (or re-discovered?) that all plants carry an electric charge relative to the ground. This charge is more or less constant regardless of the size of the plant - a kind of "background voltage" in nature.