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November 22, 2010


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Anthony Stewart EE'75

We used 3KV testers to for HIPOT safety tests on all AC powered products in production. I also used special Human and Cart model circuits for ESD simulation of discharge up to 15kV for susceptibility testing of human interface products.

Often you want to test for voltage breakdown but you don't want to induce catastrophic failure in the test process. Also the capacitance of the tester may be high enough to cause amps of discharge when you are only concerned about uA of leakage. ... So my solution in this case was to use a low capacitance 10k resistor in series inside the voltage source probe or connector. Fusing a current limiting resistor is a lot better than fusing your DUT, but typical dielectric breakdowns are momentary. At the time we were testing $200 power supplies so when failures from supplier quality issues with insufficient gaps or insulation material were detected with less risk for damage by current limiting the source.

Much like the RC divider you added to your divider.. I simply added a low capacitance current limiting resistor closest to the source to prevent similar failures. The failure mode being the capacitance discharge from source to load under dielectric stress.

Axial leaded 1/4 w resistors are typically a few pF or less.

But your



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