This presented refrigerator door open alarm circuit which alerts you after a period of time whenever your refrigerator door is left open. This circuit becomes very handy, because in case the door is left due to carelessness may cause significant increase in the consumption and affect the life of the fridge. Circuit Operation This circuit […]
Alarm
Power Switch ON Alarm with Auto OFF Circuit
In this post I have explained a simple monostable based power switch ON alarm circuit which automatically switches OFF after an adjustable preset delay. The idea was requested by Mr. Will Boswell. Technical Specifications Hi there, my name is Will Boswell. I am currently working on a project that involves adding an alarm sounder to […]
Laptop Anti-theft Security Alarm Circuit
In this post I have explained a simple laptop anti-theft alarm circuit which can used with any concerned object such as a laptop which needs to be protected, when an intruder tries to approach the unit or makes an attempt to steal it the connected alarm is instantly raised. The idea was requested by one […]
Simple Water Heater Alarm Circuit
In this post I have explained a simple water heater alarm circuit which may be used as a safety device for getting indications regarding the switched position of a water heater or a geyser through intermittent buzzer actuation. The idea was requested by Mr. Mathew. Technical Specifications To be frank i am new to your […]
Alarm Signal Generator IC ZSD100 Datasheet, Application
The ZSD100 is an alarm frequency generator IC which incorporates a frequency swept alarm signal generator designed solely for fixed and vehicle protection alarm systems. Circuit Operation For acquiring the specified alarm sound from this IC, just a single ZSD100, two timing capacitors, an in-expensive TO92 darlington, piezo transducer and coupling transformer is everything that […]
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 […]





