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Keithley 220 Voltage limit?

Posted: June 22nd, 2018, 12:15 am
by appleSwell
Hi everyone,

I set the V-Limit of Keithley 220 as 100V, but it cannot go past the current at which the voltage hits around 25V. Is there any other setup that might put a cap in voltage before the V-Limit we set on the front panel of 220? I'm running it via LabVIEW programs.

Re: Keithley 220 Voltage limit?

Posted: July 5th, 2018, 6:31 am
by brian.d.smith
Maybe you are shorting and/or loading the GUARD? The datasheet says that total (output + guard) current cannot exceed 105mA.

Make sure that you use an adapter that drops guard and does not short guard to LO/SHIELD.

You must use an appropriate triax adapter at the rear of the instrument. Using a BNC adapter will likely ruin the triax jack on the rear of the instrument.