FREE
circuits!
Recently added diagrams and projects
December 2, 2010
Producing low-distortion sine waves, this oscillator operates over the range 16 to 22000 Hz. [more]
December 2, 2010
This handy little circuit can tell the difference between darkness and light, making it very useful for switching on and off signs, porch lights or other things when it gets dark or light. [more]
December 2, 2010
Egor! Come quick! A storm approaches! Here is a VLF receiver tuned to 300 kHz designed to detect the crackle of approaching lightning. A bright lamp flashes in sychrony with the lightning bolts indicating the... [more]
December 2, 2010
This circuit will allow you to place a phone call on hold and if you wish to have them listen to music while they are on hold. [more]
December 2, 2010
This is a simple use of the PIC 16F84 about a diode tester. [more]
December 2, 2010
Have you ever been using the modem or fax and someone else picks up the phone, breaking the connection? Well, this simple circuit should put an end to that. It signals that the phone is... [more]
December 2, 2010
A small 325mW amplifier with a voltage gain of 200 that can be used as a bench amplifier, signal tracer or used to amplify the output from personal radios, etc. [more]
November 30, 2010
his simple charger uses a single transistor as a constant current source. The voltage across the pair of 1N4148 diodes biases the base of the BD140 medium power transistor. [more]
All posts