Max Johansson
Joined: 09 Jan 2006
Posts: 25
Location: Helsinki, Finland
|
 Posted: Tue Feb 13, 2007 1:03 am Post subject: Interrupting C/B link with engine running or stopped |
 |
|
Matt,
There are several reports of damaging the rectifier-regulator unit for
the Rotax permanent magnet generator if switching off with the engine
still running, just like you warn. Other reports tell about damaging
avionic equipment through overvoltage if switching off with the engine
running. On the other hand I have done that many times without any
adverse effect, once even at higher rpm in the air. After studying the
schematic of the unit I have a hunch that it is the remaining charge in
the 22mF capacitor (if fitted) that makes the regulator unit try to
output overvoltage by firing the two bridge SCRs too early during a few
cycles after breaking the connection between battery and control
connection. Fortunately I have no capacitor installed, contary to the
Rotax installation manual recommendation.
best regards
Max
RE:
From: "Matt Smith" <service(at)b-bar-daviation.com>
Subject: RE: RotaxEngines-List Digest: 3 Msgs -
02/09/07
Be sure also, that you DO interrupt the circuit between C and B+ when
the engine IS NOT RUNNING, or you will very frequently come to the
airport to find a dead battery.
Matt
| | - The Matronics RotaxEngines-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?RotaxEngines-List |
|
_________________
Max
Max Johansson, Helsinki, Finland
Building a CH701SP-912S
on CZAW amphibian floats |
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
