Hi Paul

I've just come across a reference on another list that states that Klaus
told the author that his EFI is a programmable software based system and
sighted concerns about re-booting or hanging up in flight as why he does not
want to sell it commercially as he could not offer it in a "hard silicone
version".

555 PWM constant flow or
555 regular injectors and return, has promise of simple and cheap if doable.


Clive

The way I heard it from Klaus (across the taxi way) is he did not like
computers for the reason he stated above and he is using a 555 system
instead. Try asking Paul Lipps as he designed the system for Klause. Re
booting is no big deal but when was the last time your computer crashed? Not

counting crashes caused by Windows of course:)

Paul Lamar


Paul

I posted an abbreviated version because awhile back you had said Klaus had
555, and this was opposed to your belief.

Point taken about, non-Windows crashing/rebooting.


My vote is a 555 system.

Programming a programmable system to the engine is what I think is the
problem with programmable systems.

555 would be like the old Bosch constant flow. The one with the cone shaped
airflow device would work on just about any engine if the unit was the right
size, no programming. A bit too heavy for aircraft really.


Clive

I had a talk with Klause today about this message. He mentioned some one called  him on it.  Since Paul Lipps designed the system he did not really understand what I was talking about and reiterated that his circuits had no 555 but he did not admit to a 556 which is a dual 555 or a quad 558.

In any event here is a circuit that will do the same thing and is as linear as as what ever the saw tooth circuit puts out. The saw tooth is inverted and level shifted and fed into a 311 comparator. The other input to the comparator is the zero to 5 volts from the manifold pressure sensor. The pulse width is directly proportional to the pressure sensor voltage. The main problem is changing the frequency of the saw tooth generator which I have not figured out how to do yet :)

Of course why go to all this trouble when a TLC 555 will do the same thing?
The 555 has a built in comparator and it can generate a saw tooth wave form.


BTW If one puts "pulse width versus control voltage on TLC 555" in goggle our web site comes up with the TLC 555 EFI system.


Paul Lamar