Avionics Master: Do you need a relay or a switch?

[uk_figs]

Interesting thread for me as I am just starting the wiring and have been reading the aeroelectric book trying to decide the appropriate circuit.
As I plan a dual Dynon (D100 and D120) and a straightforward SL30, GTX 327 and have a 496 it seems to me that I do not need an essential or backup bus as with the exception of the comms I have battery backup to get me home (I do have a hanheld comms). It does seem to me that I still need the avionics master to isolate everything during engine start.
I have been looking at circuits Z-11 and Z-12 as the most appropriate starting place and I would like to keep thing simple, are these the best drawings to start with? I assume I will still need a battery master switch but I confess I do not understand the alternator part of the circuit.

[RudiGreyling]

Originally Posted by uk_figs

Interesting thread for me as I am just starting the wiring and have been reading the aeroelectric book trying to decide the appropriate circuit.
As I plan a dual Dynon (D100 and D120) and a straightforward SL30, GTX 327 and have a 496 it seems to me that I do not need an essential or backup bus as with the exception of the comms I have battery backup to get me home<SNIP>

I'm with uk_figs...want it simple all electrical, no redundancy, VFR only. All the essentials D100,D120, GPS got a battery backup. That only leaves Comms. Where I fly, most of time, it is out of uncontrolled airfield, no tower, no atc. In the unlikely event I loose electric power, so be it, the plane is still flying right, your are still VFR right (VFR plane), you have a bit of battery in your GPS to get you to the nearest field yes... Decide on your mission, for your plane and kit out accordingly as simple is as possible.

I have not looked at the diagrams yet, but reading Aerolectric, so would like also to know what is best in uk_figs situation.

Regards
Rudi