Posted inMeters & Detectors
Many Simple LED AC mains voltage & current indicator circuits
We have many ways to indicates an AC line. A good way, the AC mains voltage indicator circuit with a LED. It may be the best choice. It saves and to be easy.
Posted inMeters & Detectors
6 LED voltage indicator circuits
This is four circuits of LED voltage indicator are simple and easy to builds for check voltage battery and others, use as zener,transistor,LM339 and more
Posted inMeters & Detectors
Battery voltage monitor circuit by LM339
The simple low voltage tester circuit using LM339,can use Battery voltage monitor for voltage sources that problems, by LED display and alarm sound.
Posted inMeters & Detectors
6 ranges AC millivoltmeter circuit
Sometimes, we need to measure a too tiny AC voltage level. And high frequency too. Ohh... We cannot use general multimeter. I recommend you try watching the AC millivoltmeter circuit.…
Posted inMeters & Detectors
Simple Signal injector circuits using transistors
This is simple signal injector circuit, used two transistors join together as astable multivibrator, signal output frequency 1,000Hz in square wave form.[...]