Multiple ADCs with differential amplifier

[Cloud]

I am working on a project, where we are restoring an old pinball machine. Because it will later used as educational equipment we are trying to stuff as much sensor and control circuits inside as we can. So I had an idea about measuring current through solenoids and than have ADC with microcontroller which will in case of overcurrent inform main processor. But because there are 18 (I think) solenoids I am seeking for a solution with multiple ADCs in same housing and preferably with differential amplifier since the shunt resistor will be max 10mOhm.

[pmbrunelle]

Usually in a microcontroller you have lots of analog input pins, but not many ADCs, perhaps just one. So the analog inputs are multiplexed to just one ADC.

Actually, maybe you want to have only one good quality differential amplifier. Then, you switch its input, so that it reads the different shunts (one shunt per solenoid) in sequence. This has the advantage of not needing to trim 18 amplifiers to work identically; because you're using the same amplifier for all channels, the results can be directly compared with each other more easily.