The motion sensor circuit explained in the article works by using doppler shift principle, in which the moving target is detected through the continuously varying frequency, reflected from the moving object. What is Doppler Effect One very fascinating feature of sound is the Doppler effect. The Doppler effect happens when the source that is producing […]
Sensors and Detectors
Precision Current Sensing and Monitoring Circuit using IC NCS21xR
If you are looking for current shunt monitors or current sense amplifiers then you have landed at the right page. Current shunt monitor is an instrumentation amplifier which senses the current across a shunt resistor in a system, and converts it into a logical signal output for triggering a switching device such a relay, transistor […]
Simple Touch Operated Potentiometer Circuit
In this touch operated potentiometer circuit we have two touch pads, which produce a slowly increasing voltage at the output when one touch pad is touched, and a decreasing voltage when the other touch pad is touched. When the touch contact is removed the voltage holds at that particular increased or decreased level “permanently”. Touch […]
Photodiode, Phototransistor – Working and Application Circuits
Photodiodes and phototransistors are semiconductor devices which have their p-n semiconductor junction exposed to light through a transparent cover, so that external light can react and force an electrical conduction through the junction. How Photodiodes Work A photodiode is just like a regular semiconductor diode (example 1N4148) consisting of a p-n junction, but it has […]
9 Useful LDR Circuits Explained
In this post I have explained 9 LDR circuit projects that uses LDR light sensor to trigger a load ON/OFF through a relay. These circuits are mostly triggered by the absence or the presence of light on the LDR. The circuits are built using transistors, op amps and LDR along with a switching relay. Let’s […]
Anti Spy RF Detector Circuit – Wireless Bug Detector
A anti-spy or bug detector circuit is a device that detects hidden wireless electronic devices such as wireless microphones, spy cameras, Wi-Fi devices, GPS trackers or any gadget that emits some kind of radio frequency (RF). The proposed design can be specifically used as: Overview Also called anti spy RF sniffer, these are usually used […]