This is a
simplified block diagram of a single channel.
Starting on the
left is the standoff assembly which consists of a mounting bracket, embedded
thermistor, Peltier device, and heat exchanger.
The thermisor
is wired to an A/D input.The
desired setting is output by the D/A.The difference of the thermistor and desired setting is used to
determine the drive level to the Peltier device.