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 […]
Alarm
Simple LDR Motion Detector Alarm Circuit
Here I have explained how to build a simple LDR based motion detector sensor circuit using ordinary parts such as LDRs and opamps, reasonably accurately. What are Motion Detectors Motion detector or sensor alarm is a device which detects the presence of a motion or movement within a certain fixed range and raises an alarm […]
Vehicle Speed Limit Alarm Circuit
In our previous articles we have learned comprehensively regarding the ICs LM2907/LM2917 which are fundamentally frequency to voltage converter ICs, and are ideally applicable in all such relevant fields. Here we see how the same chip can be applied for making a vehicle speed limit alarm circuit. Using a Single IC for Speed Detection As […]
433 MHz Remote Infrared Wireless Alarm
A simple infrared wireless alarm circuit can be built using an 433 MHz RF remote control unit a TSOP based IR sensor, I have explained the procedures in detail. In a few of the other posts I have discussed regarding these RF remote control modules. For more info you may go through the following relevant […]
Ultrasonic Burglar Alarm Circuit
An ultrasonic burglar alarm circuit is an electronic device which transmits ultrasonic waves to detect the movement of an intruding person. The ultrasonic waves hit the intruder and the reflected waves are picked up by the circuit. This reflected wave is used to activate a loud alarm which alerts the owner about the presence of […]
Battery Low Voltage Alarm Circuit
Despite its simplicity, the Battery Low Voltage Alarm circuit has a very important function. It forewarns you of approaching battery failure so that you may run to the store and get replacement cells before your equipment stops functioning entirely. Because of its compact size and low current need, it may be integrated into the devices […]





