07-19-2010 06:22 AM
Hi,
Is there any specification for the PXI-4461 input protection? I can not find any mention of it in the datasheet.
By misstake I connected an input to 60VDC and to my surprise it survived
07-22-2010 07:57 AM - edited 07-22-2010 08:02 AM
Hi Janaf
From the manual the PXI-4461 Analog Input looks like this:
Input Overvoltage Protection
Differential configuration ............... ±42.4 Vpk
Pseudodifferential configuration
Positive terminal......................... ±42.4 Vpk
Negative terminal (shield) .......... ±10.0 Vpk
Best Regards
David
NISW
06-09-2013 12:49 PM
Back to this old question.
Today one inputs of one 4461 was floating around like unproperly grounded.
When I pulled the unit out I could right away see that a big 49.9 ohm resistor on the input was fried. Confirmed with an ohm meter.
I am also concerned about how / where thet input DC blocking works? With 50 ohms to ground and 40V DC over it I understand the resistor would fry immediately.....
So now my question is: is there a schematic / block diagram of what the input looks like? I do not want the smoked resistor problem to happen again.
07-14-2013 05:26 AM
Thanks DaviDek,
The +/- 42.4V is also the maximum measurement range, so I gguess there is no separate overvoltage protection "absolute maximum" than that. Or at least not specified. A bit scary not to know if there is some safety margin above the max reading range..
Still, it would be good to have a block diagram on what the inputs look like in terms of DC/AC, differential / single ended, gain setting etc...