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Hi
Joe,
If the
earthling (ground) between the alternator, the engine-block, and the
system ground is not 110%, as soon as the alternator comes on-line, the
block's 'ground' voltage will rise - this will cause all sorts of havoc with the
electronics.
Just
another thought.
Charles
Been there don that. Thaks for the
input.
Joe
----- Original Message -----
Sent: Saturday, January 16, 2010 9:58
AM
Subject: [FlyRotary] Re: Alternator
Filter
Hey Joe, if the
capacitor becomes resistive and they can, you will have a dc connection to
ground.
Measure the filter
(if you haven't already) to ensure it is 100% open-circuit.
Jeff
From: Rotary motors in aircraft
[flyrotary@lancaironline.net] On Behalf Of Joe Ewen
[jewen@comporium.net]
Sent: Friday, January 15, 2010 6:12
PM
To: Rotary motors in aircraft
Subject: [FlyRotary]
Alternator Filter
I have been having problems with my engine
installation. Starts, runs great - turn on the alternator and the
engine starts to miss. Put a scope on R1 ignition trigger lead and
sure enough missing trigger pulses. Turn alternator off no more
missing pulses. Looked at the alternator output with the scope and as
expected saw some spikes. Bought an aircraft spruce alternator
filter. Ran the engine , worked fine until it would not prime or run
any more. That turned out to be a defective store switch.
Replaced the switch and back to normal. Here is the part I do not yet
understand.
Engine runs fine, added alternator filter and
can not even get a pop. Take the filter off, starts fine. Filter
back on (alt off), no joy. Filter on (alt on), no joy. Filter
off, runs fine. I can not imagine how a filter capacitor is
interfering with the ignition of the controller. If anyone has any
insight please feel to speak up.
I have 2 wiring ducts: 1. quiet - signals such
as to the PCM, ignition firing leads, low voltage sensor, analog
signals. 2. Noisy side, battery cables, ignition power, injector power
and signal (twisted pair shielded (shield properly grounded.)
Alternator connects to battery cable at the
starter. If I run an external wire between the alternator and the
battery (outside the airframe, long wire - engine in back, battery in front
(canard)) everything runs fine.) Aesthetically this might not be a good
approach, not to mention the aerodynamic impact.
This problem has kicked my butt this week
working on it in the cool 20F evening air. Any insight is appreciated,
especially why a capacitor (which does not conduct DC) would render the EC2
controller inoperative would be appreciated.
Thanks,
Joe
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