Does anyone know of a readily available chip to control the timing and duty cycle of engine fuel injectors? Or a PWM chip that could do the job equally well? Most of the ICs I'm finding seem to be entire engine management chips that do far too much other stuff whereas I only want injector control.
If you just want to drive the injector, if it is high impedance (over 12 ohms) just use a bjt or fet like it is a relay coil. If it is low impedance, generally 1.5-3 ohms, you need a peak and hold driver. Usually they ramp from zero to 4 amps in 1 msec then drop to 1 amp and hold. Cherry Semi used to make the CS452 and CS453 (different current profiles) but I'm not sure what is on the market these days. If you need the smarts that decides when to inject and for how long, that's a complete ecu :-). The Megasquirt is very popular and can be had as kits or complete. Even cheaper, there are lots of arduino based projects, just google. One such is discussed on this forum:
The first two posts give links to the hardware and two youtube vids.
----- Regards, Carl Ijames