The simple alcohol sensor 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 […]
Meters and Testers
The following posts unravel a large collection of such devices specially configured for measuring most of the parameters involved with electronic circuits.
Here you will find homemade multi-meters in the analogue range using simple opamps, and also digital meters using discrete ICs, and if you are one of those who only prefer to have custom programmed ICs in your test instruments, in that case we also have specialized Arduino based digital measuring systems.
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 […]
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 Simulation and Working Referring to the schematic, the milliohm tester is powered by two 9 volt dry cells. […]
This test set is primarily designed to test step-down, step-up transformers, for open and shorted windings. It can determine if the device under test has a low resistance to ac current. It can also measure the dc current resistance in ohms. By Henry Bowman Introduction The test set uses a 16 VAC, 60hz signal to […]
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. […]
In this post we learn 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. Simulation and Working Referring to […]