The 270 volts is bias for the pin diode switching. It’s generated with a voltage triplet off the 60 volt supply transformer.
Chuck KE9UW c-haw...@illinois.edu Sent from my iPad > On Mar 22, 2018, at 11:24 AM, Phil Hystad <phys...@mac.com> wrote: > > Is there a published circuit diagram of the KPA500, in particular the power > supply? I was curious about the design of the power supply and had a few > questions. Note: these are motivated merely by my curiosity and interest. > I have no real need to know. > > For example, the KPA500 shows a block diagram of the amplifier & power supply > and one of the voltage outputs is +270 and I was wondering what part of the > amp circuit needs 270 volts, or 60 volts for that matter. > > In idle mode, the HV display on my KPA500 reads 71 volts. Thus, not 60 and > not 270 volts. > > Another question -- the other voltages from the supply are +5, -12, and +12. > I assume these are regulated voltages. But, is the +60 and +270 regulated? > If these are regulated, what kind of voltage regulator is used. I am likely > ignorant and even possibly naive in this area as I have only used low-voltage > regulator chips and so do not even know if HV regulator chips even exist > (would they be stacked devices?). > > End of questions for now. Yes, a circuit diagram would answer all my > questions. > > 73, phil, K7PEH > > ______________________________________________________________ > 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 > Message delivered to c-haw...@illinois.edu ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
