Drivers

[Sandy]

>>Most of the automotive high perf injectors will require the CS453 (4/1)
You want to drive the small injectors with the 453's, the 452's I'm sure
will work, but at reduced performance, ie, minimum cycle time. I do not
concider the TBI injector to be in the realm of high performace injectors
like the smaller peak and hold brothers.

>
>I used to think the same thing, until I started using them (we use both;
>we have a TBI injector as the "5th/7th element" for redundant backup on
>our KISS EFI system 4/6-cyl boxers) and studied the spec more carefully.
>Here's a quote from a salient paragraph on the 3rd page of the data
>sheet.

The data sheet is wrong and in my best guess, as I have bosch, and
rochester injectors  port style  and both are specified for 4/1 drive In
addition I spoke with an engineer in some unknow place that gave me some
low down on how to drive their injectors. I think the MSD 72lbs/hr is the
rochester unit. This is not a TBI injector.  4 peak, 1 hold was how to
drive them. Thier also exists a class of injectors that are 2/1 that are
not TBI, but I think they are much more on the rare side, but who the hell
know ;-)


>
>"Automotive injectors at present time come in two types. The
>large throttle body injectors have an inductance of about 2.0 mH
>and an impedance of 1.2ohm and require the CS-453 driver. The
>smaller type, popular world-wide, has an inductance of 4.0 mH
>and an impedance of 2.4ohm and needs about a 2.0A pulse for
>good results, which can be met with the CS-452. Some designs
>are planned which employ two of the smaller types in parallel.
>The inductance of the injectors are much larger at low current,
>decreasing due to armature movement and core saturation to the
>values above at rated current."
True, and for the most part they are all satruated style drivers more often
then not. I don't know that much about the TBI, except a while ago some
used the subdriver board I made up to drive them at a 2/1 ratio. Again, I
don't know about them, don't use em'

>
>>One other side note, the cherry driver
>>is a low side switch and the lm1949 ends up being a high side switch.
>
>I dunno how you can say that, dude. The darlington's a low side switch;
>yes, the 1949 drives the darlington from the high side, but
>whatsdatgotta do with anything? The 1949 was never meant to drive
>anything all by itself anyhoo, so you end up at exactly the same place
>as the cherry drivers as far as "driver-side".

OOOOOOPS, you are right, i was looking at one thing and thinking of
another, the IRF6210's of which I am using for saturated injectors is High
side drive to the injectors. 

Sandy