This 6V continuity tester was obtained from a 1965 documentation. R1 has 150 ohm, R2 250k and R3 470k. C1 is 25 uF and C2 5 nF. Diodes are commonly used.
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This 6V continuity tester was obtained from a 1965 documentation. R1 has 150 ohm, R2 250k and R3 470k. C1 is 25 uF and C2 5 nF. Diodes are commonly used.