Paul

I had another read through the MEGASQUIRT information and it appears the
newest version of their board can control the injectors  as well as the the
MSD 6A  capacitive discharge, multiple spark ignition controller.


I am not completely clear how many of the MSD 6A units are needed for a four
plug, four coil 13B.  One for each coil?

DougFir

Can you capture the text or give me a clue about where I can read
that in the Megasquirt doc? I suspect they mean a piston engine
with a distributor.

No MSD system as far as I can tell will fire more than once at
over 3300 RPM. Here is a scr capture from the MSD6 doc.

In any event you will need four MSD systems I think. One for each
plug. Gets expensive and heavy. You might get away with three
using the waste spark trick.

Perry Mick and I are working on a rotary ignition system that
will fire six or so times at 7500 RPM for each plug.
It is complicated but it will all be in one box.

Perry, how is the tranformer coming?

Paul and Perry,

That is extremely good news you are developing something. Flyback
transformer?

In theory a capacitor is a very good way to go but if the  MSD-6  system
can't fire multiple sparks over 3300 crankshaft rpm  in a piston engine,
then the rotary will be even more rpm limited.  Correct me if I am wrong
here but  the rotary has an ignition sequence event in each rotor housing
chamber once per e-shaft revolution compared to every other revolution in a
four cylinder piston engine. This is the same as saying that multiple
discharge events will only be possible for idle speeds  at eshaft rpms below
1650?


I realize that multiple firing may be over rated and it depends on how fast
the capacitor can be recharged.  Putting aside the multiple firing issue for
now and concentrating on the other advantages of the hot and long duration
spark of the capacitor discharge system, then I think there is a way to use
one MSD-6 unit or another maker without a mechanical distributor.


Imagine this.

Each plug has its own dedicated coil and its own igniter which is basically
a heavy duty FET switch.

The capacitors (more than one is good insurance) are  wired in parallel to
the four igniters. The igniters switches are controlled by TWO firing
sequence circuits.  Each circuit receives it's sequence START signal from
one of two dedicated Hal type sensors mounted near a timing plate on the
front housing.


The sensors for the 13B would be 180 degrees offset and there would be only
one magnetized place on the  timing plate to trigger them when each front or
back rotor  was in the proper position for firing   Software would control
the initial firing time lag  and duration between the leading and trailing
firing events.

The controller sends only a small voltage to the igniter to allow them to
switch the fully charge capacitors to the appropriated coil/plug.

Seems too easy.  What am I missing?

Sorry if this has already been discussed. I haven't given ignition events a
lot of thought yet.


DougFir

I am not going to tell you more about it just yet as it
may become a commercial product. In case you are wondering
I will not receive any money from it.

Paul Lamar ...No rotor no motor.

The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net
Copyright 1998-2006 All world wide rights reserved.