Additional Injector Controller

[Scotty Grover]

Bernd Felsche wrote:

> Jörgen Karlsson tapped away at the keyboard with:
>
> > I wonder one thing about the 555, is it really possible to retrigg
> > the 555.  What happens when the trigg pulse come before the
> > previous output pulse has ended, does the 555 reset the capacitor
> > or is the trigg pulse ignored.
>
> The output remains high for the duration of the trigger pulse.
> Triggers don't reset the timer, they only start the timing process.
>
> > If the trigg pulse is ignored (I belive it is) we have a big
> > problem, the result will be that when the required injector pulse
> > width is longer then the time between the trigger pulses the
> > injectors will only be opened every other trigger event.
>
> Correct.
>
> One can however use the trigger to stretch the output.
>
> --
> Bernd Felsche - Innovative Reckoning, Perth, Western Australia
> However, according to Walter Jung, in his book "IC Timer Cookbook",  a
> P-channel JFET (Model J270 Listed) in parallel with the timing capacitor, and
> triggered by the negative-going input pulse will discharge the  capacitor with
> each trigger input, therefore holding the output "on" until the input pulses
> are too far apart to retrigger the circuit.--Scotty

----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org