In this post I have explained how to use IC 555 to create 7 interesting siren and alarm sound effect generator circuits. The versatile astable multivbrator configuration of IC 555 allows us to implement it for making various types of sirens and alarm circuits. This becomes possible because an astable is basically a waveform generator, […]
Security and Alarm
GSM Fire SMS Alert Project
In this article I will show how to construct a GSM fire alert circuit system using Arduino and DHT11 sensor, which will alert the user via text message (SMS), regarding a fire hazard within the premise where it is installed. Using DHT11 Sensor We are using DHT11 sensor for sensing unusual temperature rise around the […]
Laser Activated GSM Call Alert Security Circuit
In this post I have explained a simple laser GSM call alert security circuit which immediately calls the master as soon as an intruder is detected through a laser beam interruption. The idea was requested by Mr. Roldan. Circuit Objectives and Requirements I am not an electronic engineer, but I can manage to troubleshoot minor […]
Security Alarm Circuit using RCWL-0516 Microwave Radar Sensor
This security alarm circuit using RCWL-0516 microwave radar motion sensor will detect any moving thing in the restricted area and turn ON an alarm sound. The RCWL-0516 is basically an advanced motion sensor using microwave radar signals. I have already discussed the working of RCWL-0516 elaborately, which you can read for more details. Circuit Description The […]
Simple Motorcycle Security Alarm Circuit
In this article I have explained a simple motorcycle ant-theft security alarm circuit using a tilt switch and a TTP223 touch switch. The circuit was requested by Mr. Sergei, as given below. Design Request and Specifications I am a motorcyclist and I would like to ask you to design a simple and cheap alarm system […]
Flashlight Activated Burglar Alarm Circuit
This flashlight triggered burglar alarm circuit will instantly switch ON an alarm as soon as it detects light from the burglar’s torch or flashlight. Burglars and thieves normally set out to steal or rob during nights, when it is completely dark, and depend on a flashlight to investigate the area. Our circuit is setup and […]