modular-psu-firmware icon indicating copy to clipboard operation
modular-psu-firmware copied to clipboard

Published 20 hours ago • verified publisher icon eez-open

Output voltage offset when RSENse is not active

Open prasimix opened this issue 8 years ago • 1 comments

Maybe we should think about voltage offset when remote sense is not active. This issue is relate to the fact that due to built-in coupling circuity sense inputs are not connected right to the output terminals. Some manufacturers calls this "load compensation". Therefore with increased current we can expect significant drop when voltage is measured right on the output terminals. That can be corrected by calculating resistance value of the path between Rsense inputs and output terminals and that it into account to adjust voltage depending of measured output current.

If we are going to do something about this a related SCPI command could be [SOURce[<n>]]:VOLTage:SENSe[:SOURce] ADJusted

This compensation can be define in percentages, for each channel separately (e.g. 1.5 %). It's always negative value.

prasimix avatar Jan 15 '17 12:01 prasimix

I tried to measure voltage drop on CH1 and it seems that wiring resistance between point of internal sensing and output terminals is in average 40 mOhms:

image

prasimix avatar Feb 12 '17 16:02 prasimix