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 […]
Meters and Testers
Accurate Transistor Tester Circuits Explored
In this article we talk about a few simple yet accurate transistor tester circuits which can used to identify whether a transistor is good or bad. Note: Please test *only* BJTs and MOSFETs (enhancement or depletion) with these circuits. Simple Good/Bad Transistor Checker using a Single LED Do you have a lot of strange old transistors […]
How to Measure Very Low Current [Circuit Diagram]
Accurately measuring very low currents of a few microamps or less using a regular panel meter or multimeter is not feasible. To make such precise measurements, you need to employ an active circuit, like the one depicted here. This circuit low current ammeter circuit can be constructed as a self-contained unit or integrated into an […]
How to Make a Shunt Resistor
A shunt resistor is a very low value, high wattage resistor which is connected in parallel to a low range meter, so that it helps the meter to substantially increase its measuring capacity. Quite often you might find it hard to measure large currents with a contemporary multimeter. If you’ve ever considered buying an industrial shunt to address […]
RTD Temperature Meter Circuit
In this post I have explained the making of an RTD temperature meter circuit, and also learn about different RTDs and their working principles through formulas. What’s an RTD A RTD or resistance temperature detector works by detecting the difference or an increase in the resistance of the sensor metal when it’s subjected to heat. […]
Simple Analogue Weighing Scale Meter Circuit
Learn a super simple procedure to make a weighing scale meter circuit useful for measuring smaller magnitudes of weight. The Concept The concept is very simple, a light beam is allowed to pass through a linearly colored ribbon and fall over an LDR. The color shade of the ribbon positioned in front of the light […]