Need suggestions for the power supply solution on this design.Ideas?

Thread Starter

SandiegoSD

Joined Oct 12, 2012
18
Hi folks, I'm designing a Milli-ohm measurement test board wrt to this schematic designed by K.Wong. http://forum.allaboutcircuits.com/c...ontent/uploads/2011/08/milliohmmeasurment.png
source: http://www.kerrywong.com/2011/08/14/accurate-milliohm-measurement/
and I've finished the left half , the current source part. I did a spice simulation as below:


I'm trying to get a fairly high (500 mA ) current, so my ckt ends up pumping 10V to the positive input
to the AD8276 diff. amp. And also the Vs for the diff amp chips is using 22V(or i think 24V is fine too).

I'm looking for some suggestions on how to implement the power supply circuit/components for the final test board.

I'm planning to use wall plugs(120V), so I'd need a converter(possibly an Open Frame converter?) to bring it down to maybe 20~30V, then another component that regulates it to 22V or 24V to feed the AD8276. Also I can see I'd need something(maybe a buck converter) to generate the 10V on the positive input on the amp.
I haven't designed any voltage regulator before and have little experience . Could anyone give me some suggestions on how to achieve the conversion from 120V wall outlets to a fairly stable 22V/10V voltage ? I'd appreciate it if you could name some specific parts or designs that do this.
Thank you.
 
Last edited:

crutschow

Joined Mar 14, 2008
34,285
The easiest might be to find a wall-wart with the desired current for the 22-24V. E-bay may have some.

The 10V is low current so that could be provided by a 10V voltage regular or 10V reference IC powered from the 22V.
 
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