PID controllers offer a lot of flexibility for various types of process control, but for most of our applications (e.g. boiler temp on espresso machines), we often only use the P part. Has anyone considered using an integrated temp controller/SSR solution like the Crydom MCTC2425JLA (
http://www.crydom.com/en/Products/Catalog/m_ctc.pdf)? Although it seems like a clean and simple solution, the data sheet is silent on expected accuracy/resolution/precision and it's not a whole lot cheaper than some PIDs: digikey lists these for $106. Also, it doesn't look like there is any way to adjust the loop gain, so overshoot/convergence could be an issue.
-Phil
