This is the only other ignition in the world that is specifically
     designed for a two rotor.

     It is lower cost by about $150 compared to two Mallorys

     Probably $900 lower cost than the M&W.

     I could also include two LM1815 circuits that would
     condition the pulses out of the stock crank angle sensors
     for a few dollars more.

     If any one wants to build one I can do a circuit board for them.
-------------------------------------------------------------------------------------------

     If any body has a 2nd RX7 ignition system the waste spark coil
     will work with this CD system. You will need two for a 2 rotor.

     This will save you a lot of money. You can buy them cheap on ebay I
am sure.

     I found the old LM1815 are no longer available in dips so they must
     be surface mounted. Not that hard for this part. It can easily be done
     with a small tip on a soldering iron.

     ----------------------------------------------------
     Ops I found some LM1815 dips on ebay at a great price.
     Just over a buck apiece.

     Steve, get some of these and send some to me.
     About ten would be about right.

     Here is the schematic with the LM1815 on board.
     These are wonderful chips for taking in CAS signals
     an outputting a simple pulse. Megasquirt uses them as
     well. Why they are not making the dip versions anymore
     is a mystery to me. Dips are much easier to experiment with.

     Here is the schematic with the LM1815's.

---------------------------------------------------------------------------------------

     The other relatively expensive part is the 1 mf high voltage capacitor
     that stores the charge. It is 760 volts. I could not find one with
less voltage.

     Here it is one Digi Key for $2.83 cents each.

     Still working on the transformer.


     Paul Lamar


I would be keen  for a couple of boards,
If you are not making a few complete units.
I already have the coils lying around somewhere.

Richie Barrow

I am not ready to do the PC boards quite yet.
Steve Carlisle will take it over when I get a bit further along.

I usually order 3 PC boards at a time  as they are cheaper that way.

------------------------------------------------------

Here is the Express PCB layout for two LM1815 CAS conditioners.
16 pin dip versions.

It is to scale.
The resisters are quarter watt as I recall but  1/10 watt would work.

Attached is the pdf on the transformer I will try. I got a free
sample. They about $6 each. If they work they are a real bargain.
This is one of the hardest parts to make.

Paul Lamar

Just about any waste spark coil will work if it does not have a transistor
switch inside or igniter. In general  they would have three connections
but not always. Ground, 12 volts and a trigger connection.

In fact I am not sure if the second gen RX7 Denso will work as I found a label on
on it that said "w/igniter".  It only has two connections. And the primary is about
1 to 2 ohms.


The primary winding on these non transistor coils
is about 1 ohm.  So that will draw about 12 amps.

Use an ohmmeter to measure the primary resistance. If
it is one or two OHM it probably is a non transistor
coil. The RX7 second gen waste spark coil was about 1.5 ohms
so I assumed the 2nd gen igniter fired it.

If you connect a heavy duty push button switch from the negative side
of the coil to ground and a 12 volt battery connected to the plus side
it will fire  a simple,  old  non transistor coil with a spark plug connected
when you tap the switch.

Any coil used with a distributer with points
is a non transistor coil.

Paul Lamar

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