Low frequencies predominantly cover our earth’s atmosphere. This range of frequency may be created by many different sources which may be quite unknown and strange. A VLF sensor equipment can be made to trace these frequencies for investigating the intriguing secrets hidden behind it. Mr. Steven Chiverton investigates. VLF Receiver for Sensing Lightening and other […]
Detector
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 […]
9 Simple Metal Detector Circuits Explained
In this post I have explained 9 simple metal detector circuits using LC tuned concept, magnetic absorption concept, and the beat frequency oscillator (BFO) concept. The BFO technique is considered to be the most accurate and reliable methods of detecting metals. 1) Metal Detector Circuit Using a Single UJT The first metal detector circuit shown […]
Proximity Detector IC CS209A Pinouts – Datasheet Explained
In this post I have explained the main specifications and pinout functions of the IC CS209A along with other technical aspecst of the chip. Introduction The device CS209A is a bipolar monolithic IC specifically designed for metal detecting circuit applications. The IC fundamentally has a built-in oscillator stage, a couple of current regulator stages, a […]
How to Make a Ghost Detector Circuit
In this article I have explained to make a simple ghost detector circuit or a paranormal being detector circuit for quickly investigating a possibly infested area. Introduction Do you believe in the existence of ghosts? Well some of you may answer positively while some may just nod their heads showing sheer skepticism regarding the issue. […]
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 […]





