Re:load
Richard_Breen
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2016-07-17T18:35:40Z —
#1
Wondering if I misread instructions for current calibration. The only lab supply I had available for calibration that would support 2A output was a 5V supply that was reading 5.059 V (no load). Adjusted the voltage in calibration mode and went to current mode. Display said it was drawing 2.16 Amps, but the actual measured current (Fluke DMM) was 1.07 Amps. I adjusted the display to read 1.07 Amps and completed calibration.
After calibration I checked actual against set current up to about an Amp and the actual was always about half of the set value. Since my calibration voltage was about half of the recommended 9.99 V, I suspect something in the calibration computations may be off.
Happy for any insights.
Richard_Breen
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2016-07-24T20:45:03Z —
#2
Upgraded to version 1.11 of the firmware and re-calibrated several times before I realized what I was missing. Put two 5V supplies in series to do the calibration. NB two things:
1. The calibration seems to be accessing the power during its final stage of calibration, so don't remove or change any settings on the supply during its computations.
2. There is a new step in the calibration process since the manual was written and published -- after the current adjustment, another voltage check is done. Presumably this is a voltage under load check, but is not documented in the manual.
Hope this helps.