Small: Toy Alarm

This circuit is an alarm for the home, car and a lot more. It employs a magnet and reed switch to trigger the circuit. An intergral piezo sounder produces the alarm sound (100dB). There is also a relay capable fo handling up to 10 amps that will switch wh

An electronic circuit that uses a regular 2-inch speaker to detect for low frequency vibrations in the ground (such as those cause by a deer or human walking), and sounds an alarm.

Easy to build sound effect generator kits, inludes several different sounds and tunes.

A sensitive photo Darlington transistor is used with a CMOS nand gate. The circuit detects light and triggers a siren. You could add your own triac or relay and switch practically anything. The kit uses the MEL12 Darlington super alpha phototransistor, ty

This super sensor detector sounds an alarm if someone approaches the unit. Adds safety to your home or office. Learn the basics of motion detector technology. Uses pyroelectric infrared sensor.

The loudest peizo alarm you will find (108 to 11dB output @ 1 meter). The kit includes a resonant cavity mounting case which is molded plastic, 2" x 3-1/4" x 1-1/4", plus mounting ears. If you want to totally startle a burglar, this is the

Sometimes you need to detect water, right? Well this kit will allow you to do just that.