This digital frequency counter will provide a direct reading of the frequency applied at its input, through a 5 digit common cathode display module. The compact frequency counter can be used for accurately counting the frequency or pulse from any intended source. Main Applications It can be also used for measuring the RPM of a […]
Archives for 2020
Laboratory Power Supply Circuit
Although a variety of laboratory power supplies have appeared in recent times, only handful of these will provide you with the efficiency, versatility, and low cost of the design detailed in this article. In this article I have explained a highly regulated, DIY, laboratory grade power supply with dual 0-50 volt. The voltage and current […]
DC Shunt Motor Controller Circuit using Variac
The simple DC shunt motor controller circuit presented in the following article uses a variac. This design facilitates an instant stopping of the motor at any stage with a flick of a switch, along with reversing the motor direction. It also provides speed control for the motor with a high level of accuracy. Overview TRIAC […]
Class-D Sinewave Inverter Circuit
A sinewave inverter using class-D amplifier functions by converting a small sinewave input frequency into equivalent sine PWMs, which is finally processed by an H-bridge BJT driver for generating the mains sinewave AC output from a DC battery source. What is Class-D Amplifier The working principle of a class-D amplifier is actually simple yet extremely […]
How IC LM337 Works: Datasheet, Application Circuits
In this post I will talk about the function of an interesting voltage regulator device: The LM337, which is basically the negative complementary device for the popular LM317 IC. Built with an adjustable 3-terminal negative voltage, this regulator can conveniently supply around 1.5 A with an output voltage range of -1.2 V to -37 V. […]
Motion Detector Circuit using Doppler Effect
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 […]





