555 Timer Continuity Probe


Thanks to the folks over at 555 Timer Circuits I threw together a quick PCB layout for their continuity tester. Yes, most multimeters contain a continuity buzzer, but this is going to be part of a prototyping fixture that is currently in the planning phase. The idea is that I’ll have a breadboard, power supply, signal generator, headphone amplifier, and this continuity tester in one unit.

PCB Layout

Home Etch Friendly PDF


R1 – 10k
R2 – 33k
R3 – 1k
R4 – 39R
C1, C2 – 10nf
Q1 – 2N3904 (any general purpose NPN)
Q2 – 2N3906 (any general purpose PNP)
U1 – 555 Timer

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