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 […]
Newly Updated Circuit Projects:
Laser Diode Driver Circuit
The current controlled circuit of a laser pointer power supply explained in the following post was requested by Mr. Steven Chiverton (stevenchiverton@hotmail.com), who himself is an intense electronic hobbyist and researcher. Technical Specifications Dear swagatam, I’m emailing you to ask you for your expertise, and you being one of India’s finest electronics engineers I thought you be […]
Match Transistor Pairs Quickly using this Circuit
In many critical circuit applications, like power amplifiers, inverters, etc it becomes necessary to use matched transistor pairs having identical hFE gain. Not doing this possibly creates unpredictable output results, such as one transistor getting hotter than the other, or asymmetrical output conditions. By: David Corbill To eliminate this, matching transistor pairs with their Vbe […]
Ultrasonic Hand Sanitizer Circuit
The ultrasonic hand sanitizer circuit detects the presence of human hand through reflected ultrasonic waves, and triggers a relay solenoid pump momentarily for dispensing the sanitizing liquid on the hands of the user. The project uses the popular HC-SR04 ultrasonic sensor module for the required sensing function. Using HC-SR04 The HC-SR04 ultrasonic sensor module is […]
Ultrasonic Fire Alarm Circuit using Air Turbulence Detection
The simple ultrasonic fire alarm circuit I have explained below detects a fire hazard situation by picking up the variations in the surrounding air waves, or the air turbulence. The high sensitivity of the circuit ensures that even the slightest of air turbulence created by a temperature difference or fire is quickly detected and an […]
Loop-Alarm Circuits – Closed-Loop, Parallel-Loop, Series/Parallel-Loop
In this article I have explained a few simple loop based security alarm circuits, categorized under closed loop, parallel loop, and series/parallel loop. All these designs could be customized and used for a variety of security alarm applications. Overview In a loop alarm circuit, more than one sensor is used, each one wired with a […]





