[Diy_efi] Re: Waveforms

[Adam Wade]

Thanks for the go-ahead to move this to the list,
Mark!

--- Mark Bowers & Family <mbalntel at cfw.com> wrote:

> I think the  real answer to your question is that
> the controller is able to enable or disable the P&H
> function at will, and the designers have decided
> to enable it under idle conditions.

You think that perhaps this is an issue related to
component heating and heat sinking?  The ECU in
question has no external metal heat sink...  I suppose
it might make sense to use P&H to control idle more
precisely, and then switch to saturation driving under
such circumstances...  Allowing less heat sinking and
air circulation, but providing the benefits of P&H
with idle control.

> Based on just circuit theory, I can't think of why
> one would be constrained to drive a high impedance
> injector or low impedance injector in just P&H or
> sat modes only. The overall performance of the
> injection, particularly the timing control, would
> decide that.

Which raises an ancillary question for me; what
component ratings (particularly on the zener ahd
driver transistors) would differ when driving
high-impedance injectors via P&H, instead of
low-impedance injectors?  How would it affect
component expense and heat production?

I really want to take a further look at the behavior
of this machine now.  It's starting to sound like they
might be using a novel method of solving some
problems, and if so, it might be worthy of further
investigation for the use of list members...

=====
| Adam Wade                       1990 Kwak Zephyr 550 (Daphne) |
|   http://y42.photos.yahoo.com/bc/espresso_doppio/lst?.dir=/   |
| "It was like an emergency ward after a great catastrophe; it  |
|   didn't matter what race or class the victims belonged to.   |
|  They were all given the same miracle drug, which was coffee. |
|   The catastrophe in this case, of course, was that the sun   |
|     had come up again."                    -Kurt Vonnegut     |

__________________________________________________
Do you Yahoo!?
Yahoo! Tax Center - forms, calculators, tips, more
http://taxes.yahoo.com/

_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi