Scott, Great contribution. Surprising how many switch-mode supplies do not include OVP. AD5X created a similar circuit using a single high-peak-current transient suppressor:
http://www.radiodan.com/ad5x/images/Articles/VcondRevA.pdf Paul, W9AC ----- Original Message ----- From: "Scott Ellington" <sdell...@facstaff.wisc.edu> To: <elecraft@mailman.qth.net> Sent: Friday, August 20, 2010 4:00 PM Subject: [Elecraft] Overvoltage Protector > 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. > > > 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
