The simple LED oscilloscope circuit I have explained in this article can be used for analyzing low frequency waveform through a 10 x 10 LED matrix display. Due to the involvement of only 100 LEDs in the display board, the resolution is low, and the waveform display clarity is not so impressive. Yet, this LED […]
Meters and Testers
Alcohol Detector Meter Circuit using MQ-3 Sensor Module
An alcohol detector is a sensitive device which is able to detect the presence of alcohol molecules or any similar volatile inflammable element in the air and convert it into equivalent level of electrical output. The simple alcohol detector circuit discussed here will accurately sense the emanation of alcohol gas from a selected source, such […]
4 Simple VU Meter Circuits Explained
In this post I have explained how to build 4 interesting VU meter circuits, using LEDs and using a moving coil meter. What is a VU Meter VU meter or a volume unit meter circuit is a device used for indicating the music volume output from an amplifier or a loudspeaker system. It may be […]
Simple Transistor Diode Tester Meter Circuit
In this post I have explained how to make a simple yet efficient transistor/diode tester circuit, that will not only test the quality of a BJT, but will also help to identify whether it is is an NPN or a PNP. The circuit was designed and contributed by Mr. Henry Bowman. Circuit Operation Referring to […]
Simple MOSFET Tester and Sorter Circuit
This simple MOSFET tester does a quick job of testing both enhanced mode type N and P-channel mosfets. It checks for shorts between gate, drain and source. Designed By: Henry Bowman It also distinguishes between N and P-channel mosfets. Once the connections are correctly made to the mosfet, all testing is done without reversing connections. […]
Circuit Tester Probe – PCB Fault-Finder
This simple circuit tester probe can be used for detecting short circuits, abnormal resistance conditions, continuity breaks etc inside an assembled circuit board or a PCB. The indication will be through an audible buzzer sound or an LED illumination. The described designs are all extremely safe to use even with PCBs that may have highly […]