|
|
The schematic of revision F of the B0 version of the EC2 shows 100nF capacitors on the output of the MAP sensors.
But it really doesn't make any sense to me. Those sensors are on the PC board of the EC inside a metal box. I assume that the EC metal box in your installation is very well grounded (tougher to do in a plastic airplane).
Much more likely that wires to temperature sensor or timing pickup (CAS) would act as antenna to pick up radio transmitter signals. The CAS inputs appears well filtered on the EC2 board. So does the TempV input. But note that only the A controller uses the temperature input. Another way for RF frequencies to get into the EC2 are the wires to the control panel: Mode selector switch (PGM 0,1,2,3), Program button (PGMwrin), mixture control, etc. A ferrite coil near the box around the wires to the control panel would probably not hurt. Power supply line should be well filtered too, but may also benefit from a ferrite coil.
On the attached schematic most inputs appear to be filtered (0.1uF capacitors). You'll have to look at your EC2 installation manual and see if any inputs that could bring in RF signals are unfiltered.
Finn
On 1/11/2020 7:44 PM, Bobby J. Hughes bhughes@qnsi.net wrote:
Steve,
Tracy installed the capacitor on both MAP sensors not just the A. From memory, I believe the sensor manufacturer recommends using a capacitor in their documentation.
Shield wire for the temperature sensor might be worth a try.
Bobby
Sent from my iPad
On Jan 11, 2020, at 6:09 PM, Stephen Izett stephen.izett@gmail.com <flyrotary@lancaironline.net> wrote:
Thanks Bobby
If I cant fix the RFI at the Source I’ll pull the EC2 and check it.
Did Tracy ever explain his "long answer" as to why Processor A has had problems and not B?
All I can think of is the intake temp input.
I’m wondering how do you identify the EC2 processors as A & B when I’m looking at the PCB?
Cheers
Steve Izett
> On 12 Jan 2020, at 12:43 am, Bobby J. Hughes bhughes@qnsi.net <flyrotary@lancaironline.net> wrote:
>
> Steve,
>
> I believe Tracy started adding the capacitor to all newly built EC2/3 so you may already have it. It’s very small and was soldered across two of the three MAP sensor legs on the EC2. Not sure if it was installed the same way on the EC3’s.
>
> Bobby
>
> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
> Sent: Friday, January 10, 2020 9:20 PM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: Fwd: [FlyRotary] Re: Engine miss
>
> Thanks Andrew.
>
> So Tracy never explained the “long story”?
> Did you add the caps and did they help or not?
> I’m thinking not, as you mentioned changing to a better shield to the CAS
>
> Steve
>
> > On 11 Jan 2020, at 10:30 am, Andrew Martin andrew@martinag.com.au <flyrotary@lancaironline.net> wrote:
> >
> > Steve. Here is the post from Tracy regarding engine miss on A computer.
> > Andrew
> >
> > ---------- Forwarded message ---------
> > From: Tracy <flyrotary@lancaironline.net>
> > Date: Tue, 26 Jul. 2016, 11:22 pm
> > Subject: [FlyRotary] Re: Engine miss
> > To: Rotary motors in aircraft <flyrotary@lancaironline.net>
> >
> >
> > HI Andrew,
> > The exact cause of A having the problem and not B is a long story but the fix is to install a .1 uF capacitor across the ground and output pins (1 and 2 I think) of the A controller MAP sensor. I'd do it for you but I'm away from my shop until mid Oct.
> >
> > Tracy Crook
> >
> > Sent from my iPad
> >
> > > On Jul 26, 2016, at 03:56, Andrew Martin <flyrotary@lancaironline.net> wrote:
> > >
> > > I must have really upset Murphy, I just cannot seem to get a break with this plane.
> > >
> > > I need help from an EE or anyone who gets a kick from lectrics.
> > >
> > > Since putting the engine back in the plane I have an issue whenever I push the PTT the engine runs like crap. Finger off PTT all good immediately. And this only happens on A computer, B seems unaffected on EC2, how can this happen?
> > >
> > > A&B are tuned slightly different, B is still at pre engine rebuild state, but I cannot see how that would be a factor.
> > >
> > > I just cannot see how the Radio transmission can affect one computer & not the other, they are identical aren't they, in the same box connected to the same wires. Is it possible I've damaged the EC2 sometime in the past and just not noticed it, how would I check it now?
> > >
> > > Andrew
> > >
> > >
> > > --
> > > Regards
> > > Andrew Martin
> > > Martin Ag
> >
> > --
> > Homepage: http://www.flyrotary.com/
> > Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html
>
>
> --
> Homepage: http://www.flyrotary.com/
> Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html
>
>
> Disclaimer
>
> The information contained in this communication from the sender is confidential. It is intended solely for use by the recipient and others authorized to receive it. If you are not the recipient, you are hereby notified that any disclosure, copying, distribution or taking action in relation of the contents of this information is strictly prohibited and may be unlawful.
>
> This email has been scanned for viruses and malware, and may have been automatically archived by Mimecast Ltd, an innovator in Software as a Service (SaaS) for business. Providing a safer and more useful place for your human generated data. Specializing in; Security, archiving and compliance. To find out more Click Here.
>
--
Homepage: http://www.flyrotary.com/
Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html
|
|