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 […]
Meters and Testers
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 […]
Simple LED Forward Voltage Drop Tester Circuit
Semiconductor LEDs (Light Emitting Diodes) produce light when current flows through them. In comparison to conventional lighting sources, LEDs offer a number of benefits, including high energy efficiency, extended longevity, and low thermal output. The forward voltage drop of an LED is one of the important factors that affects how well leds performs. We will […]
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 […]
Accurate Speedometer Circuit
Here we’ll see how a simple yet accurate analogue speedometer circuit can be constructed at home using just a single IC and a few external passive components. The speedometer can be universally used with all 2-wheeler, 3-wheeler, even in bicycles for indicating their speeds. Using Frequency to Voltage Converter In my previous article I have […]
High Voltage Meter Circuit [for Measuring 10kV]
In this article I have explained a simple high voltage meter circuit which can be used for measuring extremely high voltages in the order of many 1000s of volts. The circuit can be used to measure high voltages from CDI units, Automobile spark plugs, high voltage generators, mosquito bat circuits, fence chargers, room ionizer circuits […]





