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Products => Test Equipment => Topic started by: atx on October 22, 2017, 07:36:28 pm

Title: Rigol DL3021A low current setting error
Post by: atx on October 22, 2017, 07:36:28 pm
When testing small currents, for example, currents less than 10 mA, my DL3021A does not apply the correct current until it reaches 8 or 9mA, then when dialing back to 0mA it seems to work until you reach 0mA then the trouble starts over.
For example, setting the load to 0mA applying a source voltage 3.3V shows:

current setting    read value  (manually increasing by 1mA)
=================
0.000A               0.0021A
0.001A               0.0022A
0.002A               0.0023A
0.003A               0.0023A
0.004A               0.0023A
0.005A               0.0024A
0.006A               0.0024A
0.007A               0.0025A
0.008A               0.0025A
0.009A               0.0095A  <- trigger point
once this point is reached it will work when dialing backwards until the error message at 0mA is shown then the same behavior repeats. 

The general offset of 2mA is already bad, but this hysteresis behavior is really annoying.  Range is set to 4A but it does not make a difference if set to 40A.  Slew rate changes make also no difference.
Anybody got the same erroneous behavior?

atx
Title: Re: Rigol DL3021A low current setting error
Post by: kwinz on October 09, 2019, 08:13:50 pm
Were you able to resolve this problem in the mean time?
Title: Re: Rigol DL3021A low current setting error
Post by: TurboTom on October 09, 2019, 08:48:10 pm
... so it seems Rigol didn't improve that much on the DL3000 accuracy in the last two years. You may want to compare your findings with mine (and other's as well) in this old thread (https://www.eevblog.com/forum/testgear/new-rigol-dc-load-d3000-series/msg1318288/#msg1318288).

If you need the load specifically for low current applications and you're still in the time window of returning it, you may consider to do so. There are much better loads around for low power measurements.

For high, non-changing currents though, the DL3000 may be a decent choice.