off subject

[Don.F.Broadus at ucm.com]

The two 5 lead devices are MC 348454-2 they are most likely smart power
drivers that will protect the themselves  even if the injector gets shorted.
The other power transistors are 3 lead devices and there are only one of
each. MJE 2955T ,  MTP 3055A ,  LM2930T,
I just got the manual from Holley on how to hook up the Pro Jection
controller so I can start reverses engineering the unit.




> -----Original Message-----
> From:	mswayze at truswood.com [SMTP:mswayze at truswood.com]
> Sent:	Friday, December 17, 1999 8:24 AM
> To:	gmecm at efi332.eng.ohio-state.edu
> Subject:	Re: off subject
> 
> do you perchance have numbers on the
> driver I.C.'s--I always thought they
> used transistors like an audio circuit
> or motor driver.
> thanks 
> Mike S
> 
> 
> Don.F.Broadus at ucm.com wrote:
> > 
> > Yes  the older 2 BBL projection is analog. Holley uses two RC4200 analog
> > multipliers to achieve a speed density system. The inputs to the
> projection
> > are Tach/ Coolant temp/ Throttle position sensor.   The driver I.C.'s in
> the
> > projection are a 5 lead type made by Motorola and I haven't been able to
> > find out how much power they can drive.  The power I.C. current
> capability
> > makes a difference
> > even in an analog system.
> > 
> > > -----Original Message-----
> > > From: mswayze at truswood.com [SMTP:mswayze at truswood.com]
> > > Sent: Thursday, December 16, 1999 2:16 PM
> > > To:   gmecm at efi332.eng.ohio-state.edu
> > > Subject:      Re: off subject
> > >
> > > Isn't the Projection unit analog? would
> > > this make any difference in the
> > > injectors?
> > > Mike S
> > >
> > > Don.F.Broadus at ucm.com wrote:
> > > >
> > > > Is this the 2 BBL. TBI pro jection ?  GM TBI injectors are around
> 1.2
> > > ohms
> > > > Holley should be close to this.  If the port injectors you are going
> to
> > > use
> > > > are around  12- 16 ohms  drive 4 injectors from one output and 4
> > > injectors
> > > > from the  other output. GM does the a similar  thing with a  165 ECM
> on
> > > the
> > > > 86 Camaro TPI. The injectors are  batch fired ( all 8 injectors
> > > connected in
> > > > parallel) The same ECM 165 is used on S-10 4 cyl trucks with a 1 BBL
> TBI
> > > .
> > > > The 165 ECM has only 1 injector driver and can sink current into as
> low
> > > as
> > > > 1.2 ohms. So the ECM sees a 1.2 ohm load with 8  16 ohm injectors
> in
> > > > parallel or a single 1.2 ohm injector.
> > > >
> > > > Don
> > > >
> > > > > -----Original Message-----
> > > > > From: mswayze at truswood.com [SMTP:mswayze at truswood.com]
> > > > > Sent: Thursday, December 16, 1999 12:39 PM
> > > > > To:   GMECM_DIY_EFI
> > > > > Subject:      off subject
> > > > >
> > > > > there is a Holley Pro jection computer
> > > > > on E-bay. I wonder if it would fire
> > > > > eight injectors?
> > > > > byE
> > > > > Mike S << File: Card for Mikeswayze >> << File: Card for
> Mikeswayze >>
> > > << File: Card for Mikeswayze >>