LV GigaOhm Capacitor Leakage tester
3 - 2N3904 NPN transistors used, with a DC beta of approx 220.
Clear/White LED used,
2200 Ohm LED shunt resistor can be changed to higher or lower value ( more or less sensitive) to suit personal preference.
Connection btwn Q1-Base and R2- "TESTCAP" (testing for internal leakage in capacitor) for low range of tester.
Move connection from Q1-base to Q2 Base for mid range of tester.
And move to Q3-Base for high range.
Low Range will begin to light at approx 1.2M ohm with a max test voltage of 8.5VDC.
Mid Range will light at approx 60M ohm with a max voltage of 7.7VDC .
High range will light LED at 30G ohm with a max test voltage of 7.5VDC.
The HIGH range is ridiculously sensitive for such a low voltage tester, starting to light a clear /white LED at a 30G ohm resistive short, or higher.
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