From: "Al Gietzen" <ALVentures@cox.net>
Date: 2007/04/18 Wed AM 09:44:45 EST
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: [FlyRotary] Re: Power source isolation

I find it a bit curious that the posting below that I sent on Sunday didn't
get posted until Tuesday.  Do you suppose it was intercepted and reviewed by
the 'internet police'; because there are/were a few words in there which
might have attracted attention?  All my other e-mails have been going in a
timely manner.  Anyone notice e-mails delayed on this list?

 

Al (slightly paranoid)

 

Joe;

 

We are still trying to resolve the settings [delete] issue, and have added a
number of additional filters on the board, the effectiveness of which is yet
to be proven.  Regarding the isolation diodes, I also have Schottky diodes
between the batteries and the 'hot' bus that feeds the injector and the coil
power to prevent a failure in one battery circuit from affecting the other.
It may be that noise propagated in these circuits being isolated from the
battery is a more likely an issue than isolation of the power feeds to the
EC2.

 

The reality is that after putting filters at the coils to [delete] spikes
coming back from there, we do not see any noise levels on any pins expected
to be of concern.  But since the problem still existed we assume that there
are some spikes at times we didn't observe; and in studying the circuits,
and what is different in my setup than others; we are speculating that the
isolation diodes could exacerbate the issue.  More will be known in a couple
of weeks I as get some other changes/fixes completed, and get back in the
air.  After a few low-power engine runs since the addition of the filters,
there has been no changes of settings noted so far.

 

Al