Re: Puzzling result from ESR Meter

Problem Sorted..!!!

It seems the over reading was caused by the leakage inductance of the transformer, where the capacitor partially resonates with the inductive component to give a greater current than the short circuit.

Many thanks to 'Jimmc' from EEVblog for this insite.

This has now been turned to my advantage by including the best value NON polar polycarb cap in series with the capacitor under test as a permenent mod to my meter.

Many thanks to all for your comments,
Cheer...

Re: Puzzling result from ESR Meter

Hi Multimeter, Yes that was my 1st thought when I saw the pointer fly over the zero, but no it's not that, and I have tried another NP cap several times with the same result.

Cheers

Hi I'v just finished an ESR meter based on Ludens circuit, which seems to work very well. I did a small mod to broaden the range a bit, so 4.7 ohm is below mid scale great. Works fine.

Here's the Puzzle!.

I short the test leads out to zero the meter fine.

Then If I measure a 'NON Polarized' 1.5uf polycarb capacitor it takes the meter about 5mm Past the zero point!, It also goes over the zero on another 2.2uf non polar cap I have?
How can this be?. If a short circuit limits the meter to Zero FSD. how can measuring a non Polar cap send it further...