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From: "Ian Dewhirst" <ianddsl@magma.ca>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: RE: [FlyRotary] Re: EC2 dual power feeds
Date: Tue, 7 Jun 2005 00:23:52 -0400
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Hi Charlie, my response was meant to be humorous  :-)  I guess I am not
going to make a living as a comedian.  There is a difference between
redundant and automatic though, you can have one and not the other and still
be ahead.

As far as failure modes are concerned for EC-2, I don't have a EC-2 yet and
this info probably comes in the documentation.  Out of interest, can you
think of anything in addition to the following?

Stopped running

a) Dead - caused by bad: power supply, opto-isolator or similar  for
ignition, clock section, cpu itself.

Running but not very well

a) Injector driver latched - not total failure if the injectors are sized
correctly but the injector is going to over heat and open eventually.
b) Injector driver open - again not a total failure if you organize the
injectors so that losing one will not cause a no fuel situation for one of
the rotors.
c) Failed coil driver - lose a rotor - still make some power
d) Map sensor - this could be moved up to the stopped running list, or of
this list, it depends on how much override you have with the mixture knob.
e) I don't think that Tracy uses any other sensors, I could be wrong but a
failed temp sensor circuit would not be much of a problem with the mixture
control.
f) I don't know what happens if their is a problem with the control head.
i.e. mixture pot fails etc.

External wiring problems, sensors, and CBs excluded.

Cheers -- Ian


-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On
Behalf Of Charlie England
Sent: Monday, June 06, 2005 9:23 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: EC2 dual power feeds


Unfortunately, dead is not the only possible failure mode.

Ian Dewhirst wrote:

> Technically the failed CPU is off ;-)  I thought the pilot was the
> third CPU.
>
>     -----Original Message-----
>     From: Rotary motors in aircraft
>     [mailto:flyrotary@lancaironline.net]On Behalf Of al p wick
>     Sent: Monday, June 06, 2005 8:17 PM
>     To: Rotary motors in aircraft
>     Subject: [FlyRotary] Re: EC2 dual power feeds
>
>     FWIW, I disagree .
>     -al
>
>     On Mon, 6 Jun 2005 19:07:14 -0500 "Wendell Voto"
>     <jwvoto@itlnet.net <mailto:jwvoto@itlnet.net>> writes:
>
>
>
>             In order to have truly redundant EC2s would require a 3rd
>             CPU to monitor the two controllers and automatically
>             switch the failed unit off.  Then what is going to monitor
>             the 3rd computer?
>             Wendell
>
>
>


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