At 04:40 PM 12/10/01 +0000, ashly Dearden wrote: >Is it a bad thing to use a solid state relay to control the power to a >switching power supply or is a mechanical relay a better device As long as they are rated for the surge current on connection, either type should be fine. The solid state type should be a bit better at this than the mechanical, but I'm not sure that it would be significant. Your PC power switch is relay-like contacts. -- Dave's Engineering Page: http://www.dvanhorn.org Got a need to read Bar codes? http://www.barcodechip.com Bi-directional read of UPC-A, UPC-E, EAN-8, EAN-13, JAN, and Bookland, with two or five digit supplemental codes, in an 8 pin chip, with NO external parts. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.