peak and hold fuel injector driver

[mackrackit]

Mark,
At least you have a start. By your first post I figured you have not done anything yet and was wanting to start big. My apologies.

Alan is correct, skimask is the best solution to this problem.

[mrhrholden]

whats is skimask or is this a persons name on this forum? or somthing?

[mackrackit]

whats is skimask or is this a persons name on this forum? or somthing?

That is a good question

[skimask]

That is a good question

mmmmmwwwwhaaahaaahaaaa!

LM1949 is one good one I just thought of.

[mrhrholden]

Hi Skimask

well i have already looked at the lm1949 and it will only peak and holds 8amps 1.5amps thats why i haven't gone down that track.

my injectors are .7ohm impedance and @ 12volts they pull 17amps saturated this is the reason we are making the injector drive as the Haltech E11V2 dosn't have the grunt to operate the injectors correctly its only 5amps /1.2amps even run them on a 8amp saturated and engine miss fires



Thank you mark

[skimask]

Hi Skimask
well i have already looked at the lm1949 and it will only peak and holds 8amps 1.5amps thats why i haven't gone down that track.
my injectors are .7ohm impedance and @ 12volts they pull 17amps saturated this is the reason we are making the injector drive as the Haltech E11V2 dosn't have the grunt to operate the injectors correctly its only 5amps /1.2amps even run them on a 8amp saturated and engine miss fires
Thank you mark

That's .7 ohm IMPEDANCE, not resistance. While it's basically the same thing, it's not really the 'same thing'.
As far as your original post about using the 16F84A to do this...there are much better ways. The ol' 16F84A, while it was the shiznit back in it's day and is still very useful, is wayyy outdated these days and has been superceded more than a few times.
Get a faster PIC, an 18Fxxx that'll run 40Mhz vs. 10Mhz. At least then you have the possibility of sub-microsecond accuracy (not saying you'll get it, but the possibility is there).
Get a PIC with multiple PWM outputs. There's a few out there. Use the parametric search function at www.microchip.com
And as I said before, use a REAL injector driver. National, Motorola, not sure about Microchip itself, Linear. They're out there. I'm not at the house, don't have access to my good notes for this info.

[mrhrholden]

thank you for you information will have a look for some discrete components and also look at the bigger pic18f with PWM

please let me know if you find some part numbers on some discrete's

Thank you
Mark