In article ,
"ampdoc" wrote:
"Nick Hull" wrote in message
...
Between the flywheel pickup coil (magneto) and the high voltage coil for
the spark plug there is a black box that controls the spark and its
advance. This box on My Kawasaki 3-wheeler is called the Igniter and
this simple tiny circuit board costs $400! It was designed before 1982
and contains one IC and a bunch of discrete components. There has got
to be a better (cheaper) way to do this.
The spark starts at 10 deg before Top Dead Center and advances to 40 deg
before TDC by 2000 rpm. Since electronics cannot advance time
apparently the pickup is at 40 deg BTDC and the pulse is delayed to 10
deg BTDC at low speeds. If the timing delay fails the spark reverts to
40 deg BTDC for all speeds, meaning the engine cannot run at low speeds
therefore cannot be started. Bad idea.
How could this black box be designed using components availiable today
to control the spark advance, preferably adjustable or programable so it
would work in a wide variety of ATVs etc? If possible It would be
preferable to have the failure mode at low speed advance. Certainly I
would hope for a price below $400. All suggestions welcome
--
Free men own guns, slaves don't
www.geocities.com/CapitolHill/5357/
I could see here the possibility of using a variable delay line and a
$14.00 4-wire GM ignition module say like form a late 1970's Monte Carlo,
Not sure how to make a delay line that would preserve the correct pulse
shape from the coil, however I am sure it is possible. One would rout the
signal from the pickup theu the delay to the amplifier module -- coil.
Having successfully used 4-wire GM modules to replace the two ignition
modules on a KZ-550LTD streetbike before because the spark amps from Kaw
were more expensive than the old bike, I am sure it will work, your only
problem being the timing advance, the KZ had mechanical advance.
The advance (delay) is the real problem because it is not constant in
time but must vary with crankshaft rpm even when a constant 10 deg BTDC
is needed at low speed. That's the part that has me puzzled.
--
Free men own guns, slaves don't
www.geocities.com/CapitolHill/5357/