Twin injector system?

Sandy sganz at wgn.net
Wed Jul 1 01:57:13 GMT 1998


I have though of just raising the voltage too, but would expect a couple of
problem, meltdown and destruction of the injector as one ;-). The second,
is that it might open faster, but not close faster, also I have now to dump
a lot more stored energy back into the electronics so that may require some
changes in the protection and related circutry.  I don't really know the
insides of the injector, if the fuel pressure is used to help close the
pintle (I think thats what its called), then a combination of increased
fuel pressure and higher peak voltage might do the trick. An interesting
thought, would be to take a 24 vdc powersource, and run an injector
(saturated style) with a 2/1 peak and hold current and see what kind of
minimum cycle time you can get, and then raise the pressure. I would expect
that this is all a wash, as with the added pressure the pintle will just
stick open, worth a ramble however.

Sandy

>
>The way I see it, the poor response at short cycle times is due to the long 
>rise time of the injector current, due to the inductance of the injector
coil. 
>The rise time is determined by the voltage across the injector (V=Ldi/dt and 
>all that). So, if a higher voltage could be used (e.g. using a DC-DC
converter 
>to charge a cap to say 60V or so, then dumping the energy from the cap
into the 
>injector coil at the start of the injector cycle), then the injector could
be 
>opened faster and shorter pulse widths could be used. Sort of like peak and 
>hold with a much bigger peak. The cap could be sized so that its stored
energy 
>would be just enough to open the injector. A holding current could then be 
>applied until the end of the pulse.
>
>I did a patent search and couldn't find anything similar to this, so it's 
>either a really good idea or a really bad idea. Any flames/derisive 
>laughter/questions to the list please.
>
>Ta,
>Stuart.
> 



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