I was thinking FET's would be better on power dissipation. Why would =20 you veer towards bipolars? Cheers, -Neil. Quoting Olin Lathrop : > A mechanical system like a relay is going to be less reliable than a > transistor IF the transistor is not being abused. A properly used > transistor should last indefinitely for most practial purposes. With a > inductive load like a solenoid, you have to make really sure the stored > energy in the coil is handle properly when shut off. > > The best thing would be to use transistors and make sure they are allways > run well within specs. What are the voltage and current requirements of = the > solenoids? Why do you think you need FETs? Why wouldn't a bipolar be ab= le > to do the job just fine? How fast do the solenoids need to respond to of= f > and on switch commands? --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .