Some power supplies, like the Samlex SEC 1235, have no built-in overvoltage protection. All regulated power supplies are capable of producing much more than their normal output voltage if any one of a number of things fails. Linear supplies are particularly susceptible, since the pass transistor can short.
While Elecraft assures me that the K3 can survive an overvoltage with minimal damage, I prefer to be on the safe side. So I designed a crowbar circuit, which can be used with any 12 V power supply up to 30A. If the voltage exceeds the trip point (14-16 V), it will short the power supply output and, if necessary, blow a fuse. http://www.ssec.wisc.edu/~scotte/hr/OVP.pdf I haven't built this one yet, but a very similar one I built in 1984 worked fine. 73, Scott K9MA Scott Ellington Madison, Wisconsin USA ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
