Newest circuit diagrams
Digital Step-Km Counter
Max. range: 9,950 meters with two digits. Slip it in pants' pocket for walking and jogging Read more...
SW Aerial Amplifier
A radio frequency amplifier to boost SW reception. Frequency range approximately 5 to 20 MHz. Read more...
Security Monitor
A remote listening circuit. The area to be monitored is connected via a cable and allows remote audio listening. Read more...
Infra Red Extender
This circuit was sent to me by Mr Guy Bocquillon from France. Now retired, and in his seventies, Mr Bocquillon keeps himself active in his hobby and his results and support are most appreciated. Read more...
Modular Burglar Alarm
This circuit features automatic Exit and Entry delays and a timed Bell Cut-off. It has provision for both normally-closed and normally-open contacts, and a 24-hour Personal Attack/Tamper zone. Read more...
Two-Zone Burglar Alarm
This is a two-zone alarm - with automatic exit, entry and siren cut-off timers. It can be triggered by the usual types of normally-closed input devices - such as magnetic reed contacts - foil tape - PIRs etc. I've used a 12-volt supply in the diagram - but the circuit will work at anything from 9 to 15-volts. All you need do is select a siren, buzzer and relay to suit the voltage you want to use. Read more...
Electronic Siren
An electronic siren made from discrete components. A push button switch is used to create the sound, which rises in pitch when the switch is pressed, and falls in pitch when the switch is released. Read more...
Automatic Repeater
It is a self powered (audio derived) repeater circuit for receiving a signal and re-transmitting it via the other radio. Read more...
30 Watt VHF Amplifier
The 30 watt amplifier schematic shown below provides an appropriate power boost with an input of 4 watt up to 6 watts. The circuit is designed to cover 88-108MHz FM Broadcast Band. Read more...
