Include: Volt meters :: Sound level meter :: Analog vu meter :: Soil moisture meter :: Digital meter circuit diagram :: Temperature measurements :: Electronic measurement tools :: Frequency meters :: Best battery tester :: Transistor tester project
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You have a private area, right? If you have this motion detector alarm circuit. It will reduce your worries. Imagine a big bear is coming to the behind of your house. Then, the siren alert. The big bear is shocked and runs away. You and your family are safe. Is it great? Read more
This is a Ghost Detector circuit or Static Charge Monitor circuit by Lennie. The Label was printed on card stock; clear coated with light coats of spray enamel; cut, and attached down a tomato paste can. This article was copied from Lennie Zink’s article.
The simple low voltage tester circuit using LM339,can use Battery voltage monitor for voltage sources that problems, by LED display and alarm sound. Read more
Create continuity tester circuit with buzzer and LED for check solder joint defects, not kill components on PCB, as probe gives tiny current and voltage. Read more
See LED VU meter using transistor is analog circuit to show the level of power audio signal. You can build 5 LED to 20 LED display with PCB. Read more