We all use remote control handsets for controlling various household devices such as TV, AC, Music systems, curtains etc, and sometimes we seem to have problems with these devices, or even a newly purchased remote controller unit occasionally seem to malfunction, and identifying the issue becomes quite difficult for us. This simple 2 transistor infrared […]
Newly Updated Circuit Projects:
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 […]
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 […]
Grid Dip Meter Circuit
A dip meter or a grid dip meter can be considered as a kind of frequency meter whose function is to determine the resonant frequency of an LC circuit. For this, the circuits don’t have to ‘radiate’ any waves or frequency across each other. Instead, the procedure is implemented simply by placing the coil of […]
Bicycle Speedometer Circuit
In this article I have explained how to build a simple bicycle speedometer circuit which can be used to measure the speed of the bicycle. Video Demonstration What is a Bicycle Speedometer, How it Works Bicycle speedometer is a device which checks the rotation per minute of the bicycle wheel and displays the results over […]
Light Meter Circuit with LED Bar Graph
In this article I have explained 3 different light meter circuits for measuring power of light. In the first method we will use only a solar cell and a multimeter, in the second method we will use an op amp and a moving coil meter, and in the third method we will see how a […]





