"having a separate avionics master switch?" Hi Stephen, the main reason for having an Avionics master switch is, in the case where you have something resembling a full IFR stack with multiple nav and comm units, to be able to leave them all OFF at the one time while you fire up the rest of the gear and before turning off the main breaker.
You see, all relays especially the really big ones (main contactor & starter solenoid) are just like ignition coils. After they have been energised the stored energy has to go somewhere when you turn them off and this is generally back down the wiring. A spike exceeding 600v is common and can damage sensitive radios. Having said that, if you have few radios and turn them all off individually (or have them on the one circuit breaker) before you shut down and only on again when you have the engine running you don't need the switch. For added protection always add "free wheeling diodes" to any large relay" Paul Smith Brisbane, AUSTRALIA pk.sm...@bigpond.net.au http://kr2spacemodulator.blogspot.com/ Thanks in advance, Stephen Teate Paradise, Texas _______________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
