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                           AeroElectric-List Digest Archive
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                     Total Messages Posted Sat 03/12/05: 1
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Today's Message Index:
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     1. 03:33 PM - Slowing down the ABMM  (Gilles Thesee)
 
 
 
________________________________  Message 1  _____________________________________


Time: 03:33:46 PM PST US
From: Gilles Thesee <Gilles.Thesee@ac-grenoble.fr>
Subject: AeroElectric-List: Slowing down the ABMM

--> AeroElectric-List message posted by: Gilles Thesee <Gilles.Thesee@ac-grenoble.fr>

Hi Bob and all,

Our Rotax 914 powered MCR 4S is wired per fig Z16 with dual battery and 
ABMM.
To date we have logged 17 happy flight hours and we are waiting for the 
Civil Aviation Aythority to send back the registration papers.

When fast idling, when the regulator is just below nominal voltage, the 
votage must be rapidly varying around 13 V, and the ABMM connects and 
disconnects the Aux Battery contactor at a very fast rate. The rattle of 
the contactor closing and opening at 4-5 Hz is a bit of a concern.

Here is my question :
How could I slow down the action of the ABMM ? Once every two seconds 
would seem far safer.
I imagine I could try to install a capacitor between ground and the 
sense wire. Or could a device introduce some hysteresys into the ABMM 
action ?

As the airplane is presently flying, I'd prefer to just add one or two 
components, rather than rewire the whole circuit.
Any input appreciated.

Thanks in advance,
Regards,

Gilles Thesee
Grenoble, France