Power switch for accessories?

[akarmy]

I'm wondering what you guys are doing for switching of other items besides the main Skyview screen?

ie, Transponder, ADSB, etc? I see putting the skyview on the main bus and it has a way to be turned off or rebooted if necessary, but those other items don't. Seems like they should be switched in some way to isolate if needed without having to turn off the main buss.

I'm trying to minimize my electrical design, going with a simple panel setup with one skyview display, Transponder, ADSB, backup battery etc.

Thanks!

 

[dabear]

I like things simple and have a small number of switches.

I have the SV on an "EFIS" switch with breakers for each screen in case I have to remove power from them.

I have the other items (Comm Radio, ADSB, AP Servos, ARINC, etc.) on the "Radio" Switch. I also have breakers for each of them that can be used to turn them off individually.

 

[nigelspeedy]

I used the Vertical Power VPX-Pro to do my switching. An avionics switch turns on power to all Skyview components with the exception of the Auto Pilot, which also has its own switch. If you want to turn off individual components of the system that can be done via the Engine/VPX page.
Cheers
Nigel

 

[Dynon]

We like the simplicity of minimal switches here. Have it all come on with the Master (or the Avionics switch, if you feel you must have one). Our products are all designed to handle the engine start transients. There will be more than one fuse or breaker to protect the wiring, of course. We outline the places where you'll usually want discrete circuit protection in the manual.

 

[mmarien]

You will note that when you turn the key to start an automobile the accessories shut down until you release the key. Just saying.  :-?

 

[RVDan]

Consider that accessories, including headlights, blower motors and other loads switch off making full battery capacity available to the starter. It doesn't seem like the headlights or blower motors would be affected by voltage spikes from the start relays (which all have diodes across the coils).

And consider that the engine computer, perhaps the most equivalent component to our avionics, stays on or the engine would not start.

 

[dynonsupport]

The Transponder and ADS-B both draw about 350mA, so they are hardly loads on the aircraft. They are also very robust and are happy to be on during engine start. Finally, they just flat out don't need to be "rebooted".

In my airplane, they are wired right to the same power buss as the SkyView. Why would you want SkyView on and not your transponder or vice versa? We like simple.

 

[akarmy]

Excellent. Thanks for the tips! I'll just wire them all on the main bus then. I've been able to eliminate the avionics bus since I only have the skyview system so it's getting simpler and simpler. Thanks!

 

[mmarien]

I just noticed that the Advanced Flight Quick Panel System have Avionics and AP switches. Whether they are on or off during start, I like the option the switch offers.

http://preflight.dynonavionics.com/2014/09/advanced-flight-quick-panel-system.html

 

[Dynon]

Doesn't matter really. Operationally, there's no good reason to really ever turn the AP switch off. It doesn't engage the servos, it just lets them power up and talk to the system. You need to manually activate the AP from there to actually turn the servos on. No real good reason to not treat the avionics switch like you normally would, even though our products aren't affected by the start. The way I start my airplane (Sportsman), which has a similar panel configuration, is:

-Turn left SkyView with button one to boot it on its battery to have it ready for engine crank (to see oil pressure, etc)
-Master on, prime, etc
-Crank
-Alternator switch on , avionics switch on, other switches as req