[Diy_efi] 555 timer for injector driver

[Paul Bidmead]

the best injector driver i foun was an IRF640 FET it includes a flyback 
suppressor and can handle up to 200V/16A

Kind Regards
Paul Bidmead
Design Engineer
BidSpec

----- Original Message ----- 
From: "Michael Richards" <michael at fastmail.ca>
To: <diy_efi at diy-efi.org>
Sent: Friday, July 08, 2005 12:15 AM
Subject: RE: [Diy_efi] 555 timer for injector driver


> Do not forget that you will need a flyback as well. Personally I find
> it's far easier to just buy one of those expensive national
> semiconductor injector driver chips and let it deal with the
> requirements. This way you're not limited to saturated injectors
> either.
>
> -Michael
>
>> I'd skip the solenoid to run your injector.  You're trying to control
>> a slow device (injector) with possibly an even slower device
>> (solenoid).
>>
>> Use either a Darlington transistor or a Mosfet as has already been
>> suggested.  They are not too expensive from the local Radio Shack.  I
>> use a good heat sink on the TIP-120 shown in the diagram.  When
>> running at long pulse widths, it can build some heat.  (TIP-120 was
>> used simply because it was in my parts bin, other Darlington's will
>> work.  You would want to add few other things to use the Mosfet
>> properly)
>>
>> I've attached a .pdf of the signal generator I've developed for use
>> with my projects.  Use as much or as little of this circuit as you
>> wish.  I'm only using a breadboard version at this point. I may make
>> up a PCB later this month.
>>
>> Take care,
>>
>> Dan Nicoson
>>
>>
>>> -----Original Message-----
>>> From: diy_efi-bounces at diy-efi.org
>>> [mailto:diy_efi-bounces at diy-efi.org]On Behalf Of jeff matthews
>>> Sent: Wednesday, July 06, 2005 9:39 PM
>>> To: diy_efi at diy-efi.org
>>> Subject: [Diy_efi] 555 timer for injector driver
>>>
>>>
>>> Hi-
>>> To keep my ??? simple,  I built a 555 timer to work on a little
>>> experiment,
>>> I have it energizing the solenoid on a  12v relay, why won't it open
>>> and close my injector? (it's just a basic saturated 550cc).  Is there
>>> some secret to on making an injector operate?
>>>
>>> Like I stated,  this is for an experiment, just thought I could
>>> handle making an injector fire on the bench...
>>>
>>> Best regards,
>>> JEFF
>>>
>>>
>>> _______________________________________________
>>> Diy_efi mailing list
>>> Diy_efi at diy-efi.org
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