For you guys who put in a cigarette lgihter, did you wire this through your avionics master bus, so the cig lighter won't get power unless AVIONICS MASTER is switched on? I am thinking of doing this, since it would prevent start-up currents from damaging a GPS unit if I happen to leave it plugged into the cig lighter. Thoughts?
Van's Air Force
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cigarette lighter on avionics master?
- Thread starter prkaye
- Start date
I guess that would be one mode of thinking, but what is often done is wire it directly to the battery through a 1 -2 amp fuse (in a holder adjacent to the battery). This gives you a power source without powering on the airplane which can be used to charge a cell phone (etc.) when you are away from the plane. It also gives you an emergency in flight power source for a GPS or hand held transceiver in case you have had to power down the electrical system because of a major electrical problem. Lastly, since it is connected directly to the battery you can use the power plug to trickle charge the battery if you make a plug adapter for your battery charger instead of removing the cowl for battery access..
BoilermakerRV
Well Known Member
Great Idea
I love this aspect of connecting the 12V outlet directly to the battery. Would this also work for ground power?
I love this aspect of connecting the 12V outlet directly to the battery. Would this also work for ground power?
David-aviator
Well Known Member
I have mine connected directly to the battery through a 10 amp cb. It provides for easy hook up of a battery charger.
dhammer
Well Known Member
I remember -
Back about 1975 when I tested for IA, I missed a question that asked -
If you were to install a piece of equipment such as an electric clock that wasn't shut off by the master switch, what is the maximum current rating you can fuse it for?
Darned if I remember where is said so in the regs, probably Part 21 or something, but the answer is 5 amps. Not that you can't do what you want with an experimental aircraft, but there are probably good reasons the regulations are written the way they are.
Just be extra careful with circuits that stay hot all the time you can't shut off with the master switch. That's the one that's going to short out in flight.
Back about 1975 when I tested for IA, I missed a question that asked -
If you were to install a piece of equipment such as an electric clock that wasn't shut off by the master switch, what is the maximum current rating you can fuse it for?
Darned if I remember where is said so in the regs, probably Part 21 or something, but the answer is 5 amps. Not that you can't do what you want with an experimental aircraft, but there are probably good reasons the regulations are written the way they are.
Just be extra careful with circuits that stay hot all the time you can't shut off with the master switch. That's the one that's going to short out in flight.
David-aviator
Well Known Member
Good point. It is the only live circuit, everything else is dead with the master open which is about 4" from the battery. Pulling the cb won't help much as it is on the panel next to the plug. That wire coming from the battery to it is a weak link.
It would be better to have the cb or a fuse installed near the battery.
