Hi all,
As part of a project I'm working on with my son, I lashed together
this rectified difference amplifier on a breadboard. I looked at more traditional circuits but tried this mostly because I found it interesting and it saved me some breadboard space. The stability has not been an issue for my project as I'm dealing with frequencies from mHz to a few tens of Hz (very low hundreds at most).
The inputs are a pair of TI DRV5053 linear Hall effect sensors. These sensors output between about 0 and 2V, with a 1V output with no magnetic field. One problem I'm having is that the 1V output is about +- 20-30mV and so I'm starting out with a a couple tens of milivolts offset between the sensors.
My question is, what is a good/proper way to add a method to adjust/null this offset at the input? I'm using a single supply so I think I may only be able to offset an input upwards, but that is fine for my application. I experimented with some things I found on p6 of
this TI app note, and in
this Maxim app note, but I wasn't able to get anything working.
If anyone can provide some gentle guidance it will be much appreciated.