In this post I have explained how to build a simple crystal tester circuit using ordinary parts like transistors, resistors, diodes and capacitors. What is a Crystal A crystal can be used for making an electronic oscillator circuit by using the mechanical resonance of a piezoelectric vibrating crystal to generate an electrical frequency having a […]
Meters and Testers
Make a Workbench Multimeter With the IC 741
Testing and troubleshooting electronic project circuits requires a multimeter, so new hobbyists may feel interested to try the following homemade multimeter circuits as their next electronic project. Using a Single Opamp 741 The few opamp based meter circuits such as Ohmmeter, voltmeter, ammeter are discussed below using the IC 741 and just a few other […]
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 […]
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 […]