These simple yet versatile 4 LED logic probe circuits can be used to test digital circuit boards such as CMOS, TTL or similar for troubleshooting the logic functions of the ICs and the associated stage. What is a Logic Probe A logic probe circuit is a handheld electronic tool which can be used to test […]
Meters and Testers
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 […]
Digital Thermometer Circuit – Uses a Solar Cell for Power
The articles explains a digital thermometer circuit project that works without a battery. Instead of a battery the circuit utilizes a small solar cell and operates by deriving power from the ambient light available from the surrounding light sources. This allows the circuit to be extremely compact, light weight, versatile and hassle free while measuring […]
Signal Injector Circuits for Quick Troubleshooting of all Audio Equipment
This simple signal injector circuits I have explained below can be accurately used for troubleshooting and alignment applications of all kinds of audio and high frequency equipment. 1) Using a Single IC 7400 One of the extremely handy devices for repairing audio and high frequency instruments is without question a equipment that will give you […]
10 Useful Function Generator Circuit Diagrams Explained
In this post I have explained how to build 10 simple yet useful function generator circuits using IC 4049, IC 8038, IC 741, IC 7400, transistors, UJTs etc. for generating accurate square waves, triangle waves, and sinewaves through easy switch operations. 1) Using IC 4049 Using only one low-cost CMOS IC 4049 and a handful […]
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 […]