Yngve,

Indeed, you are correct. This is within ~2%, I mention this in the original article. The resistors I used are 5% values anyway, so getting that close to 1000:1 is pretty good. You could trim the 200 k value to compensate for all the tolerances and unknowns in the circuit, including the input resistance of the meter.

One of these days I'll need to measure HV with more precision and I'll rebuild it with 1% resistors and calibrate it properly.

Regards,

Alan

Hi, just noticed your website.

With that divider of yours and a DMM input resistance of 10M (which is typical), 10M parallel to 200K will change the division ratio of the HV probe to 1021:1

Regards Yngve