Hi,
I have a bank of 6 6V batteries and I'd like to be able to measure the
voltage across each one. Would the best way be to use a diff amp as the
voltage won't be relative to ground?
If so, could someone please suggest a suitable IC that will won't go into
saturation round the 45V area?
Cheers,
Michael
chuck - 28 Feb 2007 09:30 GMT
> Hi,
>
[quoted text clipped - 8 lines]
>
> Michael
The batteries are in series and connected to a load? You can't
disconnect the load and simply measure the voltage of each battery with
a simple DMM?
I'm a bit confused by what you are trying to do, Michael.
Chuck
Michael - 28 Feb 2007 22:00 GMT
>> Hi,
>>
[quoted text clipped - 22 lines]
> ----= East and West-Coast Server Farms - Total Privacy via Encryption
> =----
Hi,
I'm building a robot that has 6 6V batteries as its power source and I'd
like to monitor each battery when the robot is operating. As it's designed
to work from some distance, I need to read the voltage and input it into the
onboard computer computer so it can be transmitted (IE I can't just use a
DMM as I won't be there to read it.)
Cheers,
Michael
Michael A. Terrell - 28 Feb 2007 22:13 GMT
> >> Hi,
> >>
[quoted text clipped - 34 lines]
>
> Michael
Resistive dividers, and a mux to an A/D converter. BTDT, and its in
orbit.

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Michael A. Terrell
Central Florida
john jardine - 28 Feb 2007 23:31 GMT
> Hi,
>
[quoted text clipped - 8 lines]
>
> Michael
For one diff' measurement it's simple to just use a standard opamp and
resistors to knock the voltage down and increase the common voltage range.
This example would put out 1/10 of the diff' voltage in. Ie 0.60V for a 6.0V
battery. That 6 volts could be sat on top of anything from 0V upto about 45V
10k
___
,----|___|---,
| |
| |
| 5V |
| -o- |
100k | | |
___ | |\| |
( - ) in o------|___|----o----|-\ | Out
___ | >----o------o
( + ) in o------|___|----o----|+/ 0-5V
| |/| o
100k .-. | |
| | -o- --o--
10k| | 0V 0V
'-'
| Opamp is a 'rail to rail' in&out type
--o--
0V
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