[EMAIL PROTECTED] made an utterance to the drakelist gang ---------------------------------------------------------------------- On Wed, 14 Dec 2005, Jim Shorney wrote:
> >All this is partially moot until he's accepting orders but i'd like to > >prepare now - i'm open to other soft start inrush limiter ideas as > >well. > > You can use NTC (negative temperature coefficient) inrush limiters such > as what is used in virtually every PC power supply these days - they > usually look like a big black ceramic capacitor. The ones in PC power > supplies are sized just about right for tube amatuer gear actually; I My only concern with thermisters is they increase HV transformer primary winding ESR and slop the HV regulation. At 50W load for a typical R-4 the voltage drop by the thermister probably isn't much, but 400W load for the AC-4 would probably reach the maximum permissible 10% voltage drop range adding to frequency drift during key down. 100VAC is too low methinks ;-) I experimented with one of them for feeding my AC-4/T-4XB and the panel lights dimmed enough to make me nervous with 80W PEP CW output. > "liberated" one from a dead PC supply and installed it in my AC4, and > there was a noticable reduction in the turn-on "thump". How much dimming effect on the panel lights do you notice with the part you used? I may have one that isn't suited for that much current draw. Hopefully Harbach will be accepting orders soon - a few of those SS-100 jobs will make my day! -- 73 Jason N1SU http://n1su.com/ ---------------------------------------------------------------------- Submissions: drakelist@www.zerobeat.net Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net ----------------------------------------------------------------------
