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Date: Thu, 21 Dec 2006 14:51:34 -0500
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Subject: Re: [LML] System level reliability
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From: "John Schroeder" <jschroeder@perigee.net>
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Fred -

If one uses the B&C voltage regulators and the circuit therein to power a caution lamp, it would be adequate to detect a pending low voltage on a buss. No? I'm not sure how the Chelton gauges are wired, but they should provide voltage readouts from the two busses, and probably current as well.

One philosophical slant for me is the use of the essential and avionics busses. They complicate the design and increase the parts count, with their consequent effect on reliability. With a reliable crossfeed contactor, you can have the same benefits of both of these busses. The only thing for the pilot would be to manually reduce the electrical load as required.

I may be able to put it all into AutoCAD when it is ready. I have all of Bob Nuckolls' Z-14 (modified) already in there. Both voltage regulator low voltage circuits have their own LED lamps on an annunciator panel in our ES.

Thanks for taking the effort to get this started.

John
>
> Looking over your design, I see one issue: Will the bus 1 to bus 2 diode keep
> you from reliably getting the low voltage warning on bus 2?
>
> Regards,
>
> Hamid