Hello David Why the diode? Well, any relay driven by a solid-state device should have a diode across its coil (in reverse polarity!) to short reverse voltage spikes. Transistor are rather fast switches... and such spikes would damage them. Never drive a relay from a transistor or IC without such a parallel diode! 73 Richard - HB9ANM
David Ferrington, M0XDF wrote: > > Now that's a good idea. Why the diode? > 73 de M0XDF, K3 #174 > -- > The soul is the same in all living creatures, although the body is > different. -Hippocrates, physician (460-c.377 BCE) > > On 14 Nov 2009, at 08:31, AD6XY wrote: > >> My K3 12V output powers an automotive relay (+diode) which connects >> the 12V >> PSU to an 8 way powerpole panel. This allows me to control the power >> to the >> LP-100A, the transverters, the KRC2 and an AT-1000pro with the K3 >> power >> switch. > > ______________________________________________________________ > 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 > > ----- Richard - HB9ANM -- View this message in context: http://n2.nabble.com/W2-tp4000196p4014449.html Sent from the [MM] mailing list archive at Nabble.com. ______________________________________________________________ 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
