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Avionics buss control suggestions

pylotttt

Active Member
looking for suggestions. I am putting in a new glass panel and I have a separate buss for avionics.
The breakers are-
MFD-5a
Comm-5a
skyfx-3a
xpdr-3a
I have an avionics switch that is rated at 20a. It's not a breaker switch just a standard on/off switch.
I have purchased a 12v 100a continuous duty solenoid from Aircraft Spruce.
Do most people? -
A- just run the avionics power from the main buss through the switch to the avionics breakers
or
B- install the solenoid and run power from the main buss through the solenoid to the avionics breakers using the avionics switch to control it.
 
I also used a relay similar to the B&C Relay, which is a DPDT relay. This allowed me to energize the avionics bus through the NC contacts, and then wire the relay control coil so the relay is energized through the panel avionics switch to turn the avionics bus off (when the switch is on, the relay is energized and the avionics bus is de-energized).

This way, if there is a problem with the avionics switch, wiring, or relay coil, the relay will be de-energized causing the avionics bus to be energized through the NC contacts, making for a lower chance of failure of power supplied to the avionics bus.
 
I also used a relay similar to the B&C Relay, which is a DPDT relay. This allowed me to energize the avionics bus through the NC contacts, and then wire the relay control coil so the relay is energized through the panel avionics switch to turn the avionics bus off (when the switch is on, the relay is energized and the avionics bus is de-energized).

This way, if there is a problem with the avionics switch, wiring, or relay coil, the relay will be de-energized causing the avionics bus to be energized through the NC contacts, making for a lower chance of failure of power supplied to the avionics bus.

So when the avionics switch is off and you flip the master on the avionics relay energizes and the power to the avionics buss is opened...
Isn’t there a momentary surge to the avionics?
 
So when the avionics switch is off and you flip the master on the avionics relay energizes and the power to the avionics buss is opened...
Isn’t there a momentary surge to the avionics?

No different than the "surge" you get when you power on the avionics buss any other way. With the low currents drawn by today's avionics, the level of "surge" is insignificant.
 
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