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Alcohol Detector Meter Circuit using MQ-3 Sensor Module

MQ-3 sensor LM393 comparator circuit

The simple alcohol detector circuit discussed here will accurately sense the emanation of alcohol gas from a selected source, such as from the mouth of a drunkard, when used as a breathalyzer. It’s cheap and a useful device which can be used by all authorized personnel such as a cops or traffic police for nabbing drunken … Read moreAlcohol Detector Meter Circuit using MQ-3 Sensor Module

Use this Capacitor Tester to Find Leaky Capacitors Quickly

capacitor tester circuit

This simple capacitor tester is capable of testing electrolytic capacitors in the range of 1uf to 450uf. It can test large start and run capacitors as well as 1uf miniature capacitors rated at 10v. Once you understand the timing cycle, you can test down to 0.5uf and up to 650uf. By Henry Bowman How to … Read moreUse this Capacitor Tester to Find Leaky Capacitors Quickly

How to Make a Simple Milliohm Tester Circuit

milliohm meter tester circuit

I wanted a milliohm tester circuit that could be used to measure resistance on printed circuit boards to track down shorted components. I looked at several designs and combined several ideas into this project. By Henry Bowman Circuit Operation Referring to the schematic, the milliohm tester is powered by two 9 volt dry cells. The … Read moreHow to Make a Simple Milliohm Tester Circuit

Simple Transformer Winding Tester Circuit

how to test transformer winding

This test set is primarily designed to test step-down, step-up transformers, for open and shorted winding. It can determine if the device under test has a low resistance to ac current. It can also measure the dc current resistancein ohms. By Henry Bowman Introduction The test set uses a 16 VAC, 60hz signal to determine … Read moreSimple Transformer Winding Tester Circuit

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. … Read moreSimple MOSFET Tester and Sorter Circuit