GDI Injector Driver Design - Page 1
Forum section: electronics / projects

author: mtechmatt
author_rank: Regular Contributor
timestamp: October 03, 2013, 09:30:04 am
content: Morning All!Right then heres one for you analog/PSU guys...What I need to do is control a new 'GDI' fuel injector (like those in petrol and deisel engines)Now these guys work as a solenoid, and they require 80-100v to throw them open, then plain old automotive battery voltage (13.2) to sustain them then a last control PWM'd signal to hold them open.The first pulse is usually around 200uS, the second pulse is usually 100uS and the final control pulse is sometimes 1000-5000uS.Now the control I can do, I'm digital and uP at heart, but its two fold, generating the DC 80-100v from a 13.2 supply (buck boost and big cap?) and switching nicely between these sources...Here is an image of what I am after, and I am open to any help, and if anyone wants to take this on at a professional, paid level, PM me(bottom of page)http://www.asnu.com/gdi.htmAnd also here is someone's research on it though they are using lab power supplys to supply their 70v, and we nee to generate ithttps://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CD0QFjAB&url=https%3A%2F%2Fredmine.fe.up.pt%2Fattachments%2Fdownload%2F2690%2F09-IJEI8-082002JE_1_.pdf&ei=BDlNUqLDM-WI0AXu0IDACg&usg=AFQjCNERSEfmviHTiHP4nyBJMTbdP5oVuA&sig2=2s6ZhFO14n0jS32bNUSDFg&bvm=bv.53537100,d.d2kMay the head scratching begin!Cheers,Matt

author: Rerouter
author_rank: Super Contributor
timestamp: October 03, 2013, 10:01:17 am
content: as your pulling a very large amount of current, it may be cleaner to build a high current boost converter with a 10Khz or better bandwidth and simply modulate the control voltage,

author: Harvs
author_rank: Super Contributor
timestamp: October 03, 2013, 10:25:03 am
content: I have no experience with these specific type of injectors. However, everything that I have worked with in the past from coil driving to low impedance injector driving had application specific devices available to perform the job under extreme conditions. If GDI injectors are on cars at the moment then I have no doubt that there's some silicon off the shelf that'll be purposely designed for the job, and will have protection schemes for things that you didn't even think of.It may just be a matter of searching under some different names for the "technology" until you find the non-patented names that the silicon manufacturers are using.

author: mtechmatt
author_rank: Regular Contributor
timestamp: October 03, 2013, 12:44:41 pm
content: Cheers for the feedback guys.In OEM ECUs they have a big capacitor, which I assume was for dumping, but yes it may be a buck boost resivoir instead?I have had a search on thw web for sillicon, freescale do some stuff but they always seem so 'closed' about it.Matt

author: mtechmatt
author_rank: Regular Contributor
timestamp: October 03, 2013, 12:52:38 pm
content: And the answer folks...

author: ConKbot
author_rank: Super Contributor
timestamp: October 03, 2013, 04:55:22 pm
content: On ford superdutys, there has been relatively constant issues with the fuel injection control modules going bad and causing problems. Perphaps more info would be available about how those work since there are quite a few online communities looking at the issue.