Capacitance Leakage Meter Has Faulty 100V Range

摘要

I built the Capacitance Leakage Meter (Silicon Chip, December 2009) and it works very well but I have one query. On the 100V scale the current under test with a shorted output is approximately 6.3mA, not 9.9mA which the text suggests is correct. I have checked all resistors for value and they all measure as specified and are in their correct positions. All other voltage/range currents are very close to that specified in the article. I cannot find any solder bridges, wiring errors or other obvious faults and the meter performs perfectly as described in all other respects. (B. D., via email).