Mailing List flyrotary@lancaironline.net Message #38418
From: James Maher <deltaflyer@prodigy.net>
Subject: Re: [FlyRotary] Switch guards, switch locks, locking switches??
Date: Sun, 15 Jul 2007 06:11:45 -0700 (PDT)
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Chris,
Being a big fool myself, I made my critical systems as foolproof as possible.
My injector disable circuit only allows one set of injectors to be disabled at a time
allowing the engine to continue to run.
See attached drawing of circuit which uses a single three position switch and relays.
With switch in center position both injectors are powered.
With switch to left or right either primary or secondary injectors are disabled and cold start is activated.
Another advantage of this setup is that a low current (inexpensive) switch can be used because the actual switching of the injectors is done by high current capacity, normally closed, relays.
As for the coil disable, I used a standard aircraft rotating ignition switch (off,left,right,both,start) with the coils connected to the mags terminals. This switch will only allow the coils to be disabled with the EC2 switched to controller "B".
There are many ways to skin the proverbial cat.
Jim

Christopher Barber <CBarber@TexasAttorney.net> wrote:
As most of y'all may know, my project is an all electric bird (Velocity SE) with a rotary engine.  Since if I loose power things get quite I am using Bob Knuckls' duel alternator/duel battery set up.  What I am curious about is the switches in the cabin.  Currently I have all the switches up high on the panel a bit right of center towards the co-pilot position.  I hope to not have a passanger who would inadvertanlty flip a switch down and off, HOWEVER, you never know what may get tangled or a stray move may flip a switch. If my coil switch or primary injectors get switched off I will start sweating.  Also, I don't really mind the switches where they are, but I do have a couple of other places I would like them, but I placed them here as to minimize being bumped.
 
My question is what other options do I have to either guard against accidental deactivation.   I have purchased a couple of aviation locking toggles from ebay, but they are kinda small and may not be up for the task (but at $13.00 for twoI couldn't go too wrong...they may work for my coil switch and primary fuel).  The regular priced DPDT (for my contactors and injectors) seem to start at close to $60.00 a piece...a bit much for my police salary if other options will surfice.
 
I have also considered installing some of the switch guards you see in old nuclear missle bunker movies that they would open to expose the firing buttons for the big ol' missles.  I considered installing them upside down (which is really easy) so that they are on when the cover is closed thus making the switch impossible to turn off by mistake. This seems really fool proof, however, the guards, while cheap, are pretty big and do not look all that, well, elligant.
 
 Also, I was watching the Astronaut Farmer last night on PPV and saw the little hard wire loops that where installed next to the switches on each side of the individual switches in his space capsule and this reminded me of the ones NASA used to use....maybe still do.  Donno.  These seem to be just half circles that make grabbing the switch very deliberate and minimizes potential knocks.  Finally, it seems as if I have seen bars held in by springs that lay across a series of switches to keep them in place. 
 
What say ye?  Insight?  Wisdom? Warnings? Observations?  WAG's?
 
Thanks.
 
All the best,
 
Chris Barber
Houston
 
crossed posted on Reflector, FlyRotary, Aeroelectric Connection email list & Canard Aviation forum

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