I’m using a PCGU1000 and need to drive a 0 - 5V triangle wave. Setting the amplitude works fine, but setting the offset produces a strange result. from 0 to -5v, everything works fine, but setting a positive offset voltage (even 0.01v) immediately drops the offset to nearly -5v. Increasing the offset towards +5v brings the actual offset towards 0 volts. The end result is that I cannot achieve a positive offset voltage. The waveform on the PC shows normal positive offset, but the actual measurements are negative.
It seems there is a circuit failure in your PCGU1000.
This may be a warranty case.
Please see: velleman.eu/distributor/support/warranty/
If you anyhow like to check the problem, you can download the circuit diagram and the lay-out drawing.
Possible cause of the problem may be: The R10 is not getting the signal from the DC7 line.
Possible cause:
- Resistor R10 is isolated.
- The soldering of pin 1 of IC7 is disconnected.
- IC7 is defective.
I recommend to send the PCGU1000 to repair.
Here the link to download the document: box.net/shared/chq5q2c85o
Thanks for your help, VEL255. The unit is 2 yrs old and is probably out of warranty (S/N 200700267), but with the docs and your advice, I repaired it. You were on target - pin 1 of IC7 was slightly bent and unsoldered. Soldering the connection eliminated all the problems. The unit is now fully functional. Thank you again for your help!
It’s good to see that you got the generator repaired!