External power for usb-6501

[rhristov58]

Hi,

I have an USB-6501 board with a one meter USB cable from NI and a ferrite clamp on it, closest to the USB board.

All is located in a 19" rack together with the PC and a high voltage/ high current pulse equipment.

Often the board resets during a pulse. I tried all shielding possible, short of optocouplers, but it did not clear the problem completely.

I looked into the USB port in the PC and found that it did not have enough capacitors on the USB power line to conform with the USB standard.

Adding external caps did not help either.

Can I use external power supply to the USB-6501?

What if I break the power lines in the USB cable and supply external power?

Thanks for any help.

[AnalogKid2DigitalMan]

---

How about an externally powered USB Isolator, here is an example:

http://www.bb-elec.com/Products/USB-Connectivity/USB-Isolators/Rugged-USB-Isolators.aspx

-AK2DM

[rhristov58]

Yes, this is a possible solution.

I just wanted to see if anyone already tried external power supply, how it was done and what are the results.

Thanks.

[SnowMule]

Alternatively, you could use an ADuM4160 IC to isolate the USB signals.  Pretty easy to implement if you're putting a custom PCB in the fixture already.

[rhristov58]

Thanks, I will try this chip, it seems promising.