This Simple Shadow Detector Security Circuit is like one guard with very sharp eyes. It uses one light sensor like photodiode to look shadow in one place. If something stop the light and make shadow then the circuit think someone is there and start an alarm. Alarm can be loud sound, blinking light or something […]
Alarm Circuits
Ultrasonic Security Alarm Circuit
Ultrasonic Security Alarm Circuit work like invisible wall for ones home. It uses very high sound wave like tiny squeaky noise which human ear can not hear it uses this to find the movement. Think like circuit sends sound wave then it waits to hear echo come back. If someone walk in the way and […]
Simple Siren Circuit
This Simple Siren Circuit article show how to make circuit sound like real siren! Sound goes up and down fast like police car or ambulance siren. Making this type of circuit is fun but remember siren are also used when emergency happens. Circuit Working: Parts List: Category Description Quantity Resistors 47k 1/4 watt 2 Capacitors […]
Infrared Alarm Barrier Circuit
This Infrared Alarm Barrier Circuit show how to use light which we cannot see to make tripwire alarm. It work like beam of light for small fences. When someone walk in front of light and break it, loud alarm make big noise to warn and scare person. It is fun project to do but real […]
Infrared (IR) Sensor Alarm Circuit using TSOP1738
This tutorial show how to make a Infrared (IR) Sensor Alarm Circuit using TSOP1738. It finds intruder using light which we cannot see. This alarm uses infrared light so people call it IR alarm. It make one invisible light beam with small chip named IC 555. If someone walk in front of light, then the […]
Infrared (IR) Intruder Alarm Circuit
This article tell how to make new type of Infrared (IR) Intruder Alarm Circuit. It can find person who walk through invisible light beam. Circuit have two main part: one transmitter and other one is receiver. Transmitter send out one infrared light beam across a room. If someone goes in front of light the LED […]