Received-SPF: none
 receiver=logan.com; client-ip=67.19.241.218; envelope-from=greg@itmack.com
Message-ID: <004a01c6f491$42ac2110$6402a8c0@NOTEBOOK>
From: "Greg" <greg@itmack.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-1488996@logan.com>
Subject: Re: [FlyRotary] Re: Injector Switches !!! was  Re: Powering fuel injectors
Date: Sat, 21 Oct 2006 07:46:37 +1000
MIME-Version: 1.0
Content-Type: text/plain;
	format=flowed;
	charset="iso-8859-1";
	reply-type=original
Content-Transfer-Encoding: 7bit

Bill the Schottky diodes are from RS (Radio Spares) I just searched through 
the specs untill I found the ones with the lowest voltage drop and highest 
current rating,  with size also being a factor. Most are 42CTQ030 from IR 
with a 40A rating you could probably try Digikey.

S4 & S6 are 4PDT switches, they are harder to find and of course more 
expensive.  They are NKK S42 and do take up a bit of room.  Originally I had 
it set up so I could select a battery but I realised that the extra 
complexity wasn't worth it and this way I'm assured that the better battery 
is supplying the engine.

Greg

> Wow, what a problem!  I switched from the daily digest to the individual
> msgs prior to asking questions so that I would get faster answers....I
> only received two msgs since I switched...This being one of them.  I
> then went to the archives and found that there had been several replies
> which I did not get..  I guess I should go back to the daily digest!
>
> The schottky diodes...I assume that you used them to reduce the amount
> that the diode pulled your voltage down?  Where did you find a supplier
> for them?  I understand that they are fairly expensive??
>
> What kind of switch is SW6  and SW14?  12 pole??? Quadruple throw???
>
> Looks like your setup would work fine.  The only real difference from
> what I was thinking is that I was trying to be able to select the
> voltage source while you are just providing a dual source with no
> selection.  Yours is probably better since my switch would provide a
> possible failure point which would kill both sources....
>
> Bill B
> ----- Original Message ----- 
> From: "Greg" <greg@itmack.com>
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Sent: Friday, October 20, 2006 9:55 AM
> Subject: [FlyRotary] Re: Injector Switches !!! was Re: Powering fuel
> injectors
>
>
> Thanks for that Ed,  I am using the EC2 but I hadn't gone through the
> install of it thoroughly yet and wasn't aware of that mode.  I'll make
> sure
> that it's done now.
>
> I follow what you're saying about breakers instead of fuses and I have
> to
> agree,  but following the Bob Nuckolls school of wiring means that the
> fuses/breakers should be no more than 6" to a foot from the power source
> (battery) and the batteries are behind the rear baggage area and no
> where
> near the panel.  The argument for the fuses to be near the source of
> electric power is also valid considering the fuses are there to protect
> the
> wiring.
>
> Greg
>
>
>> Hi Greg,
>>
>> Looks like a good electrical system over all.      However, I would
> not
>> feel comfortable with fuses in my critical system power line.  But, I
> see
>> that you are routing two power sources to each switch of your critical
>> system which means if one fuse blows due to a transit spike, the other
>> one, hopefully, will not.  Again, this is my own personal bias against
>> fuses in critical systems - there are arguments to the contrary for
> sure.
>>
>> One thing I did notice, is looking at your injector power switches, I
> am
>> not certain if these are meant to be the same as Tracy Crook's
> Injector
>> disable switches.  If they are (and they may not be), I do not see the
>> connection that automatically grounds the "cold Start" mode in the EC2
>> when either injector pair are disabled (turned off).
>>
>>  This may be a detail just not shown on the drawing - but it is
> crucially
>> important.  If the injector power switch does not have the "cold
> start"
>> grounding provision, then if you ever switch off one of the injector
>> pairs, your fuel flow will drop approx by 1/2 half.  The reason is
> that
>> (with Tracy's recommended switch set up) when you turn off one pair of
>> injectors , that automatically grounds the "cold start" pin  which
> causes
>> the EC2 to double the duration of the PW (Pulse Width) signal to the
>> remaining injector pair.  This in turn doubles the amount of fuel from
> the
>> active pair of injectors.  If the "cold start" is not activated (by
>> automatic grounding of the cold start pin through a DPDT switch) when
> an
>> injector pair is switched off,  then the PW signal does NOT double and
> the
>> fuel flow through the one injector pair will only be 1/2 of what the
>> engine needs.
>>
>>
>> Ed
>>
>> Ed Anderson
>> Rv-6A N494BW Rotary Powered
>> Matthews, NC
>> eanderson@carolina.rr.com
>> http://members.cox.net/rogersda/rotary/configs.htm#N494BW
>> http://www.dmack.net/mazda/index.html
>>
>> ----- Original Message ----- 
>> From: "Greg@itmack" <greg@itmack.com>
>> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
>> Sent: Friday, October 20, 2006 3:33 AM
>> Subject: [FlyRotary] Re: Powering fuel injectors
>>
>>
>>> I'm trying to keep the number of switched down as well,  I attached a
> pdf
>>> with my schematic which is a work in progress for your review.
>>>
>>> I have noted that a lot of builders reduce a lot of this complexity
> by
>>> just
>>> hanging everything off 1 or 2 fuses which is fine until a fuse blows
> and
>>> then everything stops.
>>>
>>> Greg RV8 down under
>>>
>>>
>>>
>>>>I am using Z-19 from the Aeroelectric Connection as a guide for
> wiring
>>>> my plane.  I would like to power the injectors from the battery
> buss.
>>>> Looking at Z-19, do I need to install a complete switch and diode
> system
>>>> for the injectors like is done for the fuel pump and ECU, or can I
> tie
>>>> on to the fuel pump OR the ECU system after either the switch (add a
>>>> separate diode) or after one of the diodes?
>>>> There will be the two DPDT switches to disable the primary and
> secondary
>>>> injectors after this connection.
>>>> My panel is becoming somewhat switch festooned and I would like to
> keep
>>>> more switches to a minimum.
>>>> How have you guys accomplished this?
>>>>
>>>> Thanks.
>>>> Bill B
>>>>
>>>>
>>>> --
>>>> Homepage:  http://www.flyrotary.com/
>>>> Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/
>>>>
>>>>
>>>
>>
>>
>> ----------------------------------------------------------------------
> ----------
>>
>>
>>> --
>>> Homepage:  http://www.flyrotary.com/
>>> Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/
>>>
>>
>>
>>
>> --
>> Homepage:  http://www.flyrotary.com/
>> Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/
>>
>>
>
>
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/
>
>
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/
>
>