Anti-Theft Car Audio Security

This small circuit uses a popular CMOS NAND gate CD4093 can be effectively used for protecting your expensive car audio system again theft,...

GSM phone ring detection

This circuit was designed to detect when a call is incoming in a cellular phone (even when the calling tone of the device is switched-off) b...

Cell phone jammer

A beautiful mobile cell phone jammer schematic diagram for use only in GSM1900 with frequency from 1930 MHz to 1990 MHz. The GSM1900 mobile...

Cellphone Scanner

Here is a device to locate the mobile phone. It emits intermittent flashes and beeps to indicate the presence of an active mobile phone. The...

Home Intercom system

In this intercom schematic, the 8 ohm speakers is used as microphone and listening speaker. The 10K potentiometer controls volume and the ...

Ultrasonic pest repeller

There are many ultrasonic pest repellers available on the market but a major drawback is that their power output is low and their effective...

White LED Flood Lamp

This White LED lamp illuminates your porch with cool white light. The circuit is too simple and energy saving design. Its current consumpti...

Octaver-Fuzz Guitar Effect Unit

The Guitar Effect Unit is good sounding octave fuzz, with an optional node of just fuzz. The fuzz is a fully rectified signal and is quite ...

Combination Lock Circuit

Combination Lock circuit This circuit is very basic to build. To open a the lock which is connected to the K1 Load. you must press each mom...