Author Topic: E3610A voltage output drifting....  (Read 403 times)

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Offline jasonbrent

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E3610A voltage output drifting....
« on: February 13, 2018, 06:08:30 pm »
Folk,

I've had an E3610A sitting on my shelf for the last few years that I used on occasion. The voltage from it was never exactly precise (e.g. 4.52volts on the display to get 4.5volts output), but it was stable. Almost no drift, at least not anything measurable with any equipment I had in the past.

I've now got a Keithley 2015 with a recent calibration, so I decided to correct that reading vs. output voltage difference. As best I can tell, I've followed the voltage calibration method from the manual (didn't calibrate current since I don't have a 0.1% 0.1Ohm 10W resistor as it prescribes).

Now when I set it to 15Volts, it's 15.000xx on the keithley, 1.00 volts is 1.000xx on the keithley... and it's stable. The last couple of least significant digits end up with no visible fluctuation....

However, if I let it sit there a few hours, I'll come back to what was 4.00 volts output and displayed as 4.11 volts output and displayed... way out of drift specs.

Before I mucked with the 10turn calibration points in it, the voltage was off, but didn't drift. now the voltage is on, but drifts a lot.

Any thoughts on how to correct it? Any other options than a 0.1% 0.1Ohm 10W resistor for calibrating current? (the closest matching resistor to the manual's recommendation I found was ~$80 USD on digikey!).

Thank you,

Jason

 

Offline Samogon

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Re: E3610A voltage output drifting....
« Reply #1 on: February 13, 2018, 06:44:41 pm »
You can use any resistor with 10w or more even use copper wire like 12-16Ga and measure it with your keithley meter to be exact.
But not necessarily same value, it can be 1 Ohm just use Ohm’s law to calculate value when doing calibration and put this value into power supply display.
 

Offline jasonbrent

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Re: E3610A voltage output drifting....
« Reply #2 on: February 13, 2018, 07:39:06 pm »
You can use any resistor with 10w or more even use copper wire like 12-16Ga and measure it with your keithley meter to be exact.
But not necessarily same value, it can be 1 Ohm just use Ohm’s law to calculate value when doing calibration and put this value into power supply display.
Makes sense... I can get away with using a spare coil made from resistance wire as I am sure I can sink 10 watts into it for a while. Thank you.

Sent from my SM-N950U using Tapatalk

 


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