New Rigol DC PSU's

[studio25]

The password for the DP832 "ManualCal" menu is "2012".

[clivew]

Yes, the DP800-series at least can be calibrated in software by going to "Utility --> Test/Cal"

Does anyone know how to use the manual test/cal screens?
I have 9.80v showing on the main ch1 output, when the voltage is set to 10v. The outuput IS 10v!
Thanks,
Clive

[Dave Turner]

I'll agree that at first glance the D832 controls looks 'kin odd and trying to set values with the recessed knob is awkward. However I've been using mine now for a month and have discovered that it is surprisingly easy to use. Consider the old style 'telephone dial' as coarse and the knob as fine, it strangely works well for me at least.

[clivew]

The password for the DP832 "ManualCal" menu is "2012".

Does anyone know the correct sequence for doing the calibration please?

Tried most ways I can think of now,

Thanks!

[jstarr]

Just got my DP832... and I notice with the channels off that I can measure (on a NIST Agilent 6 1/2 digit meter) 3.8mV @ 1.4mA out of Channel 1; and 6.9mV @ 35uA on Channel 2.  What's that about?

Also, what's with the accuracy versus display?
I set both Ch1 and CH2 to 5.000 vdc at 10mA.

Channel 1 display shows 5.007 but reads 5.00105 on the Agilent
Channel 2 display shows  5.013 but reads 5.00725 on the Agilent.

Am I correct that the displayed voltage is derived from the sensed voltage on each channel.  Is this a problem due to the common ground between the two channels? 

Whats the accuracy of the channels supposed to be and is that supposed to be correlated to the displayed/sensed voltage or the set voltage?


john

[PA0PBZ]

Whats the accuracy of the channels supposed to be and is that supposed to be correlated to the displayed/sensed voltage or the set voltage?

http://www.rigolna.com/products/dc-power-supplies/dp800/dp832/

Display Accuracy       Voltage    10mV
   With high-resolution option:   1mV

So looks within spec.

[jstarr]

I have the 1mV display option enabled.  Would you agree that is NOT within their specifications?

john

[PA0PBZ]

Ah sorry, I missed that, now you mention it it's obvious.

Well, to be honest I don't know...  There's a lot of different figures, one of them called "annual accuracy" which is 0.05% + 5mV which is about what you are seeing. And should we add up a few of those specs to get a worst case or not?

[Owen]

I have the 1mV display option enabled.  Would you agree that is NOT within their specifications?

John

It's within their specification. The accuracy doesn't change with your resolution option. The manual states: Programming voltage 0.05 % +10 mV, programming current 0.2% + 10 mA; Readback voltage 0.05 % + 5 mV, readback current 0.015 % + 5 mA.

[jstarr]

It's within their specification. The accuracy doesn't change with your resolution option. The manual states: Programming voltage 0.05 % +10 mV, programming current 0.2% + 10 mA; Readback voltage 0.05 % + 5 mV, readback current 0.015 % + 5 mA.
[/quote]

Owen, thanks that is what I was trying to understand (learn).  I didn't know that "Readback" was the Displayed Voltage.

Please help me confirm if I understand this correctly now:

So with 5.000 set, I should expect no better than +/- [(0.05% x 5.000)+10 mV]  ?  This would equal +/- [2.5mV + 10 mV] ??  So I can expect never to have single digit mV accuracy... it will always be at best 10mV accuracy?

Similarly for Readback, assuming the true output was accurately set at 5.000 vdc, the displayed readback voltage would be +/- [(0.05 % x 5.000) + 5 mV].  So any readback within 7.5mV would be within spec?

many thanks
john

[Owen]

Similarly for Readback, assuming the true output was accurately set at 5.000 vdc, the displayed readback voltage would be +/- [(0.05 % x 5.000) + 5 mV].  So any readback within 7.5mV would be within spec?

You've got it. Maybe you can tweak it a bit by calibrating your PSU once again. There's a guide how to calibrate it in the firmware/bug report thread for this device. Maybe that's what Dave/John did on his supply to get the 0.000 reading. But i'm not shure about the temperature drift of this device: Some degrees more ambient and you may could do it once again.

[jstarr]

I forgot to ask about my original problem/question.  With channels OFF I measure (on a NIST Agilent 6 1/2 digit meter) 3.8mV @ 1.4mA out of Channel 1; and 6.9mV @ 35uA on Channel 2.   Is it normal to have anything other than zero with the Channel off?   It seems the phantom voltage contributes to the error on the Readout value so not sure how calibration would improve this.  Does anyone else have a measurable voltage/current when channels are OFF?

thanks
john

[nack]

Isn't it just the output capacitors discharging trough your meter?

[jstarr]

Isn't it just the output capacitors discharging trough your meter?

I don't think so for two reasons : 1) I have left the DMM connected for >12 hours and no drop in voltage or current; 2) if I set the supply voltage for 5.000 vdc and power the Channel on - the readout will show .... 5.000 + the off-channel voltage.  In my case for example the off voltage on Ch2 is 6.95 mV and the DP832 readout show 5.007v.  So the readout, sensor is correct as my DMM, it seems there is some phantom output even with channel off.

Can I connect a dead short across the channel + and - to see if this removes the Off phantom power?

PLEASE- can someone check if this happens on their DP832 or explain this observation?

thanks
john

[K1JOS]

Isn't it just the output capacitors discharging trough your meter?

I don't think so for two reasons : 1) I have left the DMM connected for >12 hours and no drop in voltage or current; 2) if I set the supply voltage for 5.000 vdc and power the Channel on - the readout will show .... 5.000 + the off-channel voltage.  In my case for example the off voltage on Ch2 is 6.95 mV and the DP832 readout show 5.007v.  So the readout, sensor is correct as my DMM, it seems there is some phantom output even with channel off.

Can I connect a dead short across the channel + and - to see if this removes the Off phantom power?

PLEASE- can someone check if this happens on their DP832 or explain this observation?

thanks
john

I just checked my brand neww DP832A and I am seeing the same thing (somewhat different values) on my DP832A on Ch1 and CH2 with power off.  Maybe we should start a new topic about this?

Jerry

[Owen]

I forgot to ask about my original problem/question.  With channels OFF I measure (on a NIST Agilent 6 1/2 digit meter) 3.8mV @ 1.4mA out of Channel 1; and 6.9mV @ 35uA on Channel 2.   Is it normal to have anything other than zero with the Channel off?   It seems the phantom voltage contributes to the error on the Readout value so not sure how calibration would improve this.

They probably don't switch the unit "off" they just set current and voltage to zero. If you'll turn the channel on and set the current and voltage down to zero it should show the same results.

[K1JOS]

I forgot to ask about my original problem/question.  With channels OFF I measure (on a NIST Agilent 6 1/2 digit meter) 3.8mV @ 1.4mA out of Channel 1; and 6.9mV @ 35uA on Channel 2.   Is it normal to have anything other than zero with the Channel off?   It seems the phantom voltage contributes to the error on the Readout value so not sure how calibration would improve this.

They probably don't switch the unit "off" they just set current and voltage to zero. If you'll turn the channel on and set the current and voltage down to zero it should show the same results.

I found the same issue on my new DP832A.  So if this is an "incorrect" zero volt /zero current setting then a re-calibration should correct it?  Is that your thinking?  Would be good news .

jerry

[K1JOS]

John, it looks like it all can be corrected by the DAC and ADC calibration.  I just completed Ch1 calibration and now have 0.0000 output with Ch1 OFF and I have very good output accuracy based on my recently calibrated 6.5 digit Agilent meter.  I then found the ADC readout was off by almost 0.5v but I calibrated that as well and now everything is within 1-3 mV of where it should be.  Wow, that is super-cool !!   

The only odd thing is that the calibration date still shows up as the factory calibration date of Sept xx 2013.

Jerry

[Owen]

I found the same issue on my new DP832A.  So if this is an "incorrect" zero volt /zero current setting then a re-calibration should correct it?  Is that your thinking?  Would be good news .

Sorry for that late response. Yes thought that should do it. Thank you for your verification - good job .

[K1JOS]

Well, I spoke too soon. I was able to correct the voltage output and voltage readout very easily on CH1 but I didn't bother to check CH2 right away.  Seems CH2 has the same kind of problem with set voltage, output voltage and readout voltage all being different.  I went through the V-DAC calibration first and the output now on CH2 is perfect.  But it is reading about 0.9V higher than the output.  It seems to only do this fopr low outputs < 0.5v.  I found it readsout 0.9v higher right up to a setting of 0.500 (at 0.500 the readout says 1.378v) but when I increase the output setting to 0.501V – the readout drops to within an acceptable value of 0.505v.  Very bizarre.  I also then tried the autocalibrate V-ADC button and it gave a message that calibration failed.  In some threads it warned to wait at least 3 sec after entering the measured voltage before hitting 'input value' but this made no difference.  It seems the DP832A has problems and this is my second one !!  Well its going to go back to Tequipment for now.

jerry

[K1JOS]

Tequipment provides great customer service !!  They contacted Rigol and sent me latest firmware 01.09 and I recalibrated the V-ADC.  Now output, readout are near perfect and match exactly what I see on my Agiloent DMM for all 3 channels.

thanks again Tequipment (Evan)

Jerry
K1JOS

[clivew]

Supplier who worked very well for me all the way is Telonic Instruments Ltd. (www.RIGOL-uk.co.uk) . I had some in-depth technical queries and Telonic was able to sort it and
Dave won't spin you a yarn. I screwed up the v1.09 upgrade on my DP832.
Returned it to them, they returned it fully calibrated at no charge!
Subsequently, when I bought the Hi-Res Option from them, the key didn't work.
It turned out that v1.09 needs a different key, which Dave got for me, and now
all is good

[ted572]

This is the new for 2014 Rigol DP800 Calibration guide.

[shrek]

Has anyone tried to hack the DP832's ANALOG board? Any luck with JTAG and full memory dump of the controller?

[nbritton]

Has anyone tried to hack the DP832's ANALOG board? Any luck with JTAG and full memory dump of the controller?

Bump. Also did Rigol fix the overheating issue with the LM317?