The LM34 looks like a good way to tempco just about anything. (CEM3374 Paul?) Digi-Key LM34DZ-ND $2.63 http://www.tomg.vivid.net/misc/lm34.gif The LM331 looks like it could be the cornerstone of a F/V converter. Digi-Key LM331N-ND $8.26. http://www.tomg.vivid.net/misc/lm331.gif -tg