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 […]
Simple
Very Simple BLDC Motor Driver Circuits using Back EMF
In this post we investigate what’s a BLDC motor and subsequently I have explained regarding the design of a sensorless BLDC motor driver circuit. BLDC CPU Fans Seen those fast moving fans in CPUs, voltage stabilizers, DVD players, and other similar equipment, which work with utmost efficiency, consuming minimum space, current and yet are able […]
Simple TV Transmitter Circuit (Audio and Video Combined)
The TV transmitter circuit presented in this post incorporates the European standard FM frequency for audio and Video up-links. Referring to the circuit below, Q1 is configured as a preamplifier for amplifying the audio input to be modulated. Circuit Description Q2 is fundamentally responsible for conducting a couple of important functions: It amplifies the carrier frequency […]
Simple Frequency Meter Circuits – Analogue Designs
The following simple analogue frequency meter circuits can be used for measuring frequencies which may be either sine wave or square wave. The input frequency which is to be measured must be at least 25 mV RMS, for optimal detection and measurement. The design facilitates a relatively wide range of frequency measurement, right from 10 […]
Simple Digital Clock using LM8650 IC Circuit
The digital time clock explained here is a circuit which most electronic amateurs would love to make. You might have heard about digital clocks made from clock ICs such as the popular LM8361, MM5387 etc but these ICs could be today quite obsolete and/or complex to build. Circuit Operation The present design is much easier […]
5 Simple DC Motor Speed Controller Circuits Explained
A circuit which enables a user to linearly control the speed of a connected motor by rotating an attached potentiometer is called a motor speed controller circuit. 5 easy to build speed controller circuits for DC motors are presented here, first one using MOSFET IRF540, second one using IC 555, the third concept with IC […]