Injector Driver Module

[Don.F.Broadus at ucm.com]

I got the spark info from the 2nd edition bosch handbook . spark rate per
min = 8cyl.* 6000 RPM/2=24000 sparks per min24000/60=400sparks per second.
Or if you don't like that formula    Frequency = 8 cyl *6000 rpm/120 = 400
HZ
These pulses would be on the TACH terminal of the coil. 
 
Don
	-----Original Message-----
	From:	Shannen Durphey [SMTP:Shannen at mcn.net]
	Sent:	Monday, August 10, 1998 2:15 PM
	To:	diy_efi at efi332.eng.ohio-state.edu
	Subject:	Re: Injector Driver Module

	Which pulses were we discussing?  6000 RPM=100 cps, but
	takes 2 crank revs to fire 8 cylinders.  So, each plug wire
	fires 50times/sec, and coil or coil wire is 400 (50*8)
	times/second.  Also, during synchronous firing, one primary
	side coil pulse=one injector pulse.  With 8 injectors tied
	together, is 400hz.  Split into two banks of four, is 200hz
	each.  Sequential is 50hz each.  

	mrvette wrote:
	> 
	> Say what?  at 6000 rpm.....ign. pulses are 100 hz....and so are
injector pulses
	> in sequential......if batch it's dviided by 4     not the pulse
width, but the
	> rate.....GENE
	> 
	> Don.F.Broadus at ucm.com wrote:
	> >
	> > I'm working on an  injector driving module also. If you are
going to fire
	> > the injectors sequentially, then one injector would be on at a
time in the
	> > firing order sequence (1-8-4-3-6-5-7-2 GM V-8)  If you are going
to batch
	> > fire the injectors
	> > Then only 4 would be on at a time.  The factory heat sinks on
the driver
	> > transistors are not that big so I doubt that the power
dissipated is very
	> > high.  The duty cycle is a combination of on time and off time,
so even at
	> > 85% the injector would
	> > Only be on for less than half of the time. The frequency of the
injector
	> > pulse needs to be known, at 6000 rpm the ignition
	> >  pulses are 400 HZ. I would guess that the injector pulses would
be the same
	> > frequency for sequential firing and half of that for batch
firing.  So far
	> > my bench setup is a batch fire with  2msec on time at idle  and
10 msec at
	> > wot. Any advice would be appreciated.