Anti Theft Alarm

Two Zone Intruder Alarm circuit
This is a two-zone alarm which featured with automatic exit, entry and siren cut-off timers. The circuit will activate the alarm if any intruder entering the zone/room. When you move SW1 to the Set position - you have about 30 ...

Fire Alarm Circuit with Thermistor and NE555
Above circuit is an fire alarm circuit which build using a fire alarm sensor component and sound generator component. With simple and cheap component, you can build this circuit for low cost. The termistor is a fire detector sensor and ...

Rain Alarm
For some areas that are facing the rainy season like in my place, this Rain Alarm circuit project might be a little helpful to give warning that there will be rain. This is helpful, for example if you are inside ...

Cpu Cooler Failure Alarm
The device is designed to beep when you stop the fan that cools the CPU PC (ie, cooler). The indicator is included in the break cord fan, the size of the PCB 40x32.5 mm (fits into a matchbox). Schematic diagram ...

Police Siren circuit
This is a police alarm circuit.  The two 555 timer ICs used as astable multivibrators. The frequency is controlled by the pin 5 of the IC. Actually, the sound is genereted by combination of sound from both IC 555. One ...