Dan: If the Astron is working AS INTENDED, when the OVP SCR fires, the UA723 VReg will immediately go into over-current protect mode, reducing the output current to <1A WITHOUT damaging ANYTHING! Same as if you placed a short directly across the output terminals of the supply.
The ONLY time the fuse should blow is if the p ass transistors shorted. 73, Tom Hammond N0SS At 20:28 02/28/2010, you wrote: >I recently purchased a 35 amp Astron power supply at a hamfest (in >great condition). Upon inspection, I found that the crowbar SCR had >failed, and had been removed. > >Although I've replaced the SCR, I'm wondering if the K3 has >overvoltage protection of some kind? > >As an aside, I would like to test the crowbar circuit in the Astron, >but with that big capacitor in there, I'm kind of hesitant. That >big capacitor would have to discharge before the primary fuse would >blow (maybe blowing the SCR)--right? I'm thinking of putting a 25 >amp fuse in series with the capacitor. Anyone address this before? > >Thanks, >Dan - W4TQ >______________________________________________________________ >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 ______________________________________________________________ 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
