Hi Forrest,

      I like Denny's out of the box ideas. How about "in the box", =20
but one less opamp?

      Have you seen, the Sparkfun ACS712 Low Current Sensor Breakout @?

http://www.sparkfun.com/products/8883

      More importantly, the schematic half way down the page, if this =20
url doesn't work,

http://www.sparkfun.com/datasheets/Sensors/ACS712%20Low%20Current%=20
20Sensor%20Board%20v12.pdf

     Uses 1 inverting opamp + resistors, but you can put the current =20
through the input of the ASC712 in either direction to get the =20
correct sense on the opamps output. Offset and gain are variable.

     Just been looking at this for a PIC project.

Heinz

On 23-Jun-11, at 10:10 AM, Forrest Christian wrote:

> I have a circuit which I now plan to use an allegro ACS711 current
> sensor.  This puts out voltage based on current, where zero current is
> referenced to VCC/2.   As I only care about current in one direction,
> I'd really like to remove this offset and then be able to amplify this
> to a range based on my expected current range.
>

......<snip>....

>
> Thanks,
>
> -forrest


--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.