Posted inSound Generator
4 Simple Door Buzzer Circuits
Use low voltage so safe. I am boring old buzzer. When use AC line, danger of leakage power in the heavy rain, 3 circuits can help you!..
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Posted inAmplifiers
Simple Telephone Ring Amplifier circuits
The telephone repeater circuit or The call signal peripheral circuit to the loud than the original,with a buzzer or a electric bell, to increase loud sound