 |
Matronics Email Lists Web Forum Interface to the Matronics Email Lists
|
View previous topic :: View next topic |
Author |
Message |
leo(at)icn.usyd.edu.au Guest
|
Posted: Sun Mar 02, 2008 6:19 pm Post subject: Ignition control in a dual alternator dual bus system |
|
|
Dear List,
I am currently designing the electrical system for my "all-electric" RV
10. I have been very happy with Bob's architecture for my RV6A which
worked beautifully the day my alternator died in the clouds.
I am looking at the Z-14 schematic which involves two batteries, two
alternators and a cross feed for starting and for electron sharing in
failure mode.
I note that there are no switching diagrams for mags or other ignition
systems on this diagram. I wondered what the implications for mag
switching were in this setup. Should they just have simple switches but
only turn on the impulse coupled mag for a start? If so, how serious are
the implications if the non-coupled mag is accidentally enabled at
startup? If I ran an electronic system on the left would you only turn
this on after start and again stick with impulse coupling on the
standard mag for the start.
I would be pleased to hear from anyone who has used this schematic as
the basis for their electrical system as to how they had handled the
ignition switching.
Thanks for your help.
Leo Davies
--
A/Prof Leo Davies,
Sub-Dean, Head of Assessment,
Faculty of Medicine,
Edward Ford Building,
University of Sydney 2006
| - The Matronics AeroElectric-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
Back to top |
|
 |
mlas(at)cox.net Guest
|
Posted: Mon Mar 03, 2008 6:59 am Post subject: Ignition control in a dual alternator dual bus system |
|
|
Leo,
I just wanted to respond to the ignition issues you raised. First if
you use an impulse coupling then you should inhibit the non-impulse mag
during the start. If you go with an electronic system with variable
timing then you should start with both systems on. When using an
ignition system with variable timing you should run two, not one mag and
one electronic system. The only exception to the mag vs. electronic is
if the maximum advance on the electronic is the same at the mag. This
will enable you to gain the highest horse power at the highest power
setting. The idea behind having an electronic ignition system is to
have variable timing and a hotter spark. The problem with one mag vs.
one electronic is you give up horsepower and fuel efficiency when the
timing is different. The unit that has the most advance will fire first
thus starting the combustion cycle early as it compares to the other.
In most cases the mag will be the first to fire at lower power setting
thus eliminating a retarded timing giving you better idle and starting.
At takeoff power the electronic system will in most cases advance beyond
the mag causing you the loss of power gained from the mag system during
that period.
Something to think about,
Mike
--
| - The Matronics AeroElectric-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
Back to top |
|
 |
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum You cannot attach files in this forum You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|