GIGAOHM_CAP_LEAKAGE_TESTER_1

Updated on 09-2023 to reflect changes made for production of PCB device. 3 - 2N3904 NPN transistors used, with a DC beta of approx 220. Clear/White LED used, 2K Shunt Trimpot can be adjusted to higher or lower value ( more or less sensitive) to suit personal preference. Switches S1 to S3 connect NEG TEST lead from base points on Q1 ( LO), Q2 ( MED) and Q3 (HI) sensitivity With R3 set to a mid range value of 1K, high range will begin to light LED at 30G ohm with a max test voltage of 7.01VDC, Mid Range will light at approx 100M ohm with a max voltage of 7.5VDC .Low Range will begin to light at approx 600K ohm with a max test voltage of 8.3VDC. The HIGH range is ridiculously sensitive for such a low voltage tester, starting to light a clear /white LED at a 30G ohm, or higher, resistive short. Ground on NEG battery terminal is only on schematic to make meters functonal, it is NOT used or needed in real life device.