I have a project that will have a number of thermistors. It will require measurement of temperatures higher than the range digital sensors can accommodate. Rtds and thermocouples would be expensive. I would like suggestions as to whether use the thermistor as the input resister with the transdiode in the feedback loop of the op amp, or to use the transdiode as the input with the thermsitor in the feedback loop. In either case I plan on using an analog multiplexer to switch in different thermistors.
Since matched pair transistors and logamps are no longer readily available at a reasonable prices, I have a different idea to use a circuit similar to how a chopper op amp functions to cancel out temperature variations in the transdiode. The way I figure it, there's no better match for a transistor than itself anyway. However that will be the subject of a different thread.
Since matched pair transistors and logamps are no longer readily available at a reasonable prices, I have a different idea to use a circuit similar to how a chopper op amp functions to cancel out temperature variations in the transdiode. The way I figure it, there's no better match for a transistor than itself anyway. However that will be the subject of a different thread.