This is a low cost, simple, yet a surprisingly powerful electronic siren powered by just a 9V battery. The circuit may provide the final circuit […]


This is the diagram of heat detector circuit which already integrated with siren circuit in the output. This circuit applies a complementary pair comprising NPN […]

Here the circuit diagram of safer security system alarm. There are many security systems use a closed loop of wires and switches arranged so that […]

Here is the circuit diagram of simple multitone alarm. This is a low cost circuit which is simple and easy to build. The main components […]

This is door knob touch alarm for your home security purpose. The alarm will be activated when someone touch the metal door knob. This circuit […]