Differential Amp

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

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

Resistive dividers, and a mux to an A/D converter. BTDT, and its in orbit.

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

(created by AACircuit v1.28 beta 10/06/04