Newest circuit diagrams

Ultrasonic Dog Whistle

It's well known that many animals are particularly sensitive to high-frequency sounds that humans can't hear. Many commercial pest repellers based on this principle are available, most of them operating in the range of 30 to 50 kHz.

One-Time-Only Burglar Alarm

This alarm is designed to sound its Siren only once. That is - when the alarm is activated - the Siren will sound for a preset length of time. Then it will switch off and remain off. The alarm will not re-activate.

Cmos Based Single Zone Alarm

This circuit features automatic Exit and Entry delays - timed bell cut-off - and system reset. It has provision for normally-open and normally-closed switches - and will suit all of the usual input devices (Pressure Mats, Magnetic Reed contacts, Foil Tape, PIRs and Inertia-Sensors).

Sound Modifier

Four shape-controls portable unit. Wide variety of output waveforms

3 Band Equalizer

A tone control circuit made with a single op-amp and having three ranges, bass, middle and treble controls.

150W MP3 Car Amplifier

LF353 Wide Bandwidth Dual JFET Input Operational Amplifier

VCS using 555 Timer

In this circuit the 555 timer is used in a novel way, as a voltage controlled switch.

Motorcycle Alarm No. 2

This circuit features an intermittent siren output and automatic reset. It can be operated manually using a key-switch or a hidden switch; but it can also be wired to set itself automatically when you turn-off the ignition. By adding external relays you can immobilize the bike, flash the lights etc.

Tremolo Effect Generator

Stand-alone, 9V battery powered unit. High overload margin, low distortion circuit

LEDs or Lamps Sequencer

Very simple, versatile modular design. No limits to the number of modules used in the ring