I am breadboarding up a version of your 555 circuit, and was wondering if
you could provide any ball park figures for the unvalued components
(capacitors, Leaning pot, R1 and damping resistor), or ball park pulse width
range.
I know the damping resistor was mentioned in an earlier post, but I'm
currently working from web-mail, and cannot access my archives.
I'm substituting a TLO31 for the op-amp, and a 2N6660 for the FET, just
because that's what I have laying around.
Do the injectors require fluid flows for self cooling?
Sorry to be a burden.
C. Smith

On the damping resistor ask JCP. I have no idea what he has in mind.

Here are the remaining values.

-----------------------------------
ops forgot the drawing.
Here it is.

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I don't think that op amp circuit is going to work.
I am going to get a Ti INA 122 instrument amp and fool around with it.
Minimum gain is 5 so I will probably try the leaning pot on the input side
of the inst. amp.

If you have a variable voltage supply I would feed that into the TLC 555 for
now. Just for demo purposes.


Paul Lamar

Yes, I have a variable supply, but that would be too easy. I think I can
come up with a workable circuit for the op amp too, now that I have some
time.
C. Smith

I think the constant is the control voltage out of the mass airflow
sensor. It is zero to 5 volts. There may be a trade off between that
and the supply voltage. I need to take a closer look at that. According
to the data sheet it is rated full on at 66.7% of supply
voltage so the supply looks like it needs to be 9 volts.

This is not your grandfather's 555 :)

Paul Lamar