Hi If you received this earlier my apolgies, I neglected the ":" after the topic tag. Hi People I am not sure if this is the correct forum or not. I am building a small system with PIC control which has to switch large currents +30A at 12/24V. The frequency is quite low i.e. once per hou. This is not really my area so I need some advice. Without wanting to start WWIII what do others see as the pros and cons of the various methods electronic and mechanical. Thanks for any input. Jon -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu