dean.psiropoulos(at)veriz
Guest
|
 Posted: Sun Nov 11, 2007 12:12 am Post subject: Avionics-List Digest: 2 Msgs - 11/05/07 |
 |
|
Functional checkout of my electrical system has gone well so far with no
smoked wiring or equipment. I bought an equivalent of an Odyssey 680 a
couple years ago and trickle charged it occasionally hoping it would at
least be good enough to do electrical checkout, first engine start and maybe
a few times around the pattern. But it appears that is not the case.
Voltmeter says there is 12.5 volts at the terminals but it can't produce
enough amps to fire the battery contactor or even make some sparks when
shorted, pretty pathetic. I substituted a Panasonic 4.5 amp hour sealed lead
acid battery that I bought second hand about 6 years ago. It's got enough
oomph for the checkout but I'll need a new 680 for 1st engine start.
I did a test on my magneto P-leads (one mag on left side, electronic on
right side)with an ohm meter. Thinking that when the key switch is in the
off position, the resistance across the p-lead should measure close to dead
short and, it does. By the same logic, I thought that when the mag was
ungrounded the resistance across the p-leads (I used a shielded wire with
the shield grounded at the magneto through the key switch, no local
grounding). But when I measured across the p-leads at the magneto the
resistance only went from 0.2 ohms to 0.4 ohms when I turned the key. Not
an appreciable increase in resistance but it was consistent (happens every
time) and measurable. I thought maybe I had a faulty key switch but not so,
I removed one p-lead from the mag and made the same measurement and the
resistance with the key in that mag's position read infinite. I suspect
that there is some thing about magnetos I don't know and that this is not a
problem but would like to be sure. Anybody ever done this test? Did you get
the same results?
Also checked out the VM-1000 and it seems to work fine except for dimming.
I used one of the B&C dimmers connected to the VM-1000 dimming input but I
don't seem to get any dimming action (backlight works ok). Anyone else
experience this? Have I missed something in the VM manual and it doesn't use
an external dimming input? Any thoughts? Thanks.
Dean
RV-6A N197DM
closer to 1st flight.
| | - The Matronics Avionics-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?Avionics-List |
|
|
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
