In this article I have explained a couple of very easy to build RF detector circuits, which can be used to sense or detect or sorts of Rf electrical noise that may be floating in the surrounding atmosphere. What is RF RF stands for radio frequency, which is a kind of electrical interference transmitted in […]
Detector
5 Simple Motion Detector Circuits using PIR
A PIR motion sensor alarm is a device which detects the infrared radiation from a moving human body and triggers an an audible alarm. In this post I have explained 5 simple motion detector circuits using op amp and transistor. We also discuss the pinout details of the standard passive infrared (PIR) sensor RE200B. We […]
Simple Mobile Phone Detector Circuit [Tested]
A cellphone or mobile phone detector is actually a high gain op amp amplifier which detects slightest of RF disturbance from a mobile phone, and illuminates an LED. Mobile phones today being the major generator of RF interference is easily picked up by this circuit and can be seen through an LED illumination at the […]
Non Contact AC Phase Detector Circuit [Tested]
The circuit discussed in this article is of a non-contact mains AC field detector which displays the presence of a mains AC field from a distance of more an 6 inches. Locating Fault in AC Lines without Physical Contact The circuit can be used for locating faults in house wiring without the need of making […]
Simple Peak Detector Circuit to Detect and Hold Peak Voltage Levels
In this article I have explained about a peak detector circuit, its working principle and how to implement it in clap operated circuits for illuminating an LED in response to clap sounds. What is Peak Detector A peak detector is a circuit which holds maximum amplitude value of a signal. If a signal varies rapidly […]
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 […]





