From 04:00 PM CDT – 08:00 PM CDT (09:00 PM UTC – 01:00 AM UTC) Tuesday, April 16, ni.com will undergo system upgrades that may result in temporary service interruption.

We appreciate your patience as we improve our online experience.

Home Community Discussion Forums Most Active Software Boards LabVIEW Topic

LabVIEW

cancel
Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for 
Search instead for 
Did you mean: 

Voltage measuement advice (USB6216)

Voltage measuement advice (USB6216)

‎08-06-2017 06:59 AM

Labels:

Hi All,

 

Please advise,

 

I am having some difficulty measuring a votlage using a USB 6216 (A task which i usually do not have an issue with). Please see attached pic.

 

The device under test is a 12 volt power supply with the secondary side optically isolated from the mains votlage side. I am placing a votlage divider at the O/P (220k/100K) and measuring the voltage over the 100K resistor, differentailly using AI1+ and AI1- as shown. I have have connected the AI reference to ground (also shown).

 

Can someone please advse me if this is good/ correct practice or not ? My measurments are not as stable as i would like...

 

thanks in advance.

0 Kudos
Message 1 of 2
(2,144 Views)
Reply

Re: Voltage measuement advice (USB6216)

‎08-06-2017 02:45 PM

You will have issues with ghosting and other noise due to the divider making a high impedence source.  I would add an op-amp in a voltage follower configuration to create a single ended signal that will also have a low source impedence.

GCentral
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines
"Not that we are sufficient in ourselves to claim anything as coming from us, but our sufficiency is from God" - 2 Corinthians 3:5
0 Kudos
Message 2 of 2
(2,098 Views)
Reply