The front panel on/off switch is an input to the microcontroller. The microcontroller runs all the time that DC power is applied. The back panel switch interrupts the microcontroller's power supply.
When the front panel turns the KPA500 off, it turns off the HV power, dumps the power into the fans, releases all the internal relays, and turns off the front panel display. The microcontroller stays on to monitor the serial port. The KPA500 can be turned "on" again by a command from the KPA500 Utility or another program attached to the KPA500's serial port. A lot of consumer electronics, including my TV set and phone, aren't really "off" unless unplugged. 73 de Dick, K6KR -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Keith O'Brien Sent: Wednesday, August 29, 2012 6:53 AM To: [email protected] Subject: [Elecraft] KPA500 Power Switches I took delivery of my KPA500 a few weeks ago and I am pleased with it. However I was some what disappointed that the manual did not come with a schematic diagram of the amplifier. This has got to be my first piece of ham radio equipment that I have owned in half a century that did not come with a diagram. The lack of a schematic now leads to this question. Just what is it that the front panel ON switch is turning on and off ? The rear panel power entry module switch does kill all power to the amplifier, but the front panel switch when Off, leaves some circuit power up. Anyone know what is left power on when the front panel switch is OFF and the rear panel switch is On ? Having the main On Off power switch on the rear panel is a bit of a inconvenience in my shack.Also having just only one RF output connector is problematic. Guess that is what the KAT500 with it's 3 Output connectors is for.... Keith N4ZQ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] 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:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
