Issue with Power Supply

[ryannguyen94]

Hello,

I'm trying to find a good way to supply power to the sbRIO. I'm hoping to use an AC/DC wall adapter to connect the sbRIO directly to the outlet. However, I can't really find any AC/DC adapter that can produce ripple less than 20mV, which is required for the sbRIO. Most of them produces 1% ripple, which I think is equivalent to around 200mV (sbRIO requires 19-30 VDC). Before this, I used a AC/DC power supply because its ripple satisfies the requirement (0.1% -> 20mV), but it is expensive and large, and I don't like that. So my question is do you guys know any AC/DC wall adapter that can output such small ripple? or do you know a better way (cheaper and more compact than a ACDC power supply) to supply power to the sbRIO?

English is not my native language, so sorry if I cause any confusion.

Thanks,

[j_bou]

Hello ryannguyen94,
 
You might not be able to find a cheaper and smaller version of a power supply with 0.1% ripple. However, I would recommend contacting a company which makes power supplies to receive a definitive answer.
 
XPPower:
http://www.xppower.com/EN/AC-DC-power-supplies
 
CUI INC:
http://www.cui.com/catalog/power/ac-dc-power-supplies
 
What sbRIO hardware are you using (i.e. model number)? Where did you find the ripple requirement of 0.1% ripple for the sbRIO your are using?
 
Regards,
 
j_bou

[ryannguyen94]

Thanks for your response,

My sbRIO is sbRIO 9632. Here is the manual:

http://www.ni.com/pdf/manuals/375052c.pdf

On page 16, it says that the power supply should have ripple less than 20mV

[Spex]

I believe that 20mVpp ripple specification was limited in order to acheive the analog accuracy specifications.  The power supply for the analog input and output sections of that board are not isolated (like they would be with physical C Series modules) so noise on the power supply (especially the negative/ground terminal) can propagate to the analog input measurements.  

The biggest risk of using a power supply with a larger ripple specification is added noise on the analog input and output measurements.  If you are OK with this possibility, then a power supply with larger ripple (say 200 mVpp, which is more common) may be OK.  That really depends on the goals of your applications and potential impact of noise on your analog measurements.

Regards,