Ignition updates to the Unofficial FAQ

"Michael Pardee" > wrote in
:

> ----- Original Message -----
> From: "TeGGeR®" >
> Newsgroups: rec.autos.makers.honda,alt.autos.acura,alt.autos.h onda
> Sent: Saturday, June 04, 2005 8:37 AM
> Subject: Ignition updates to the Unofficial FAQ
>
>
>> Jim Yanik .> wrote in
>> :
>>
>>
>>>
>>> Something additional I thought of after I sent the last
>>> post(sorry!); The ECU does not ground the igniter module.It only
>>> sends a signal (to the control IC inside the igniter)for the
>>> Darlington to ground the coil.
>>
>>
>> Then how do you explain this?
>> http://www.tegger.com/hondafaq/misc/rov-ign.jpg
>> Look at the text immediately below the title.
>>
>
> That was how Jim got into the semantic trap to start with. The ECU
> supplies a low current ground to pin 4, which grounds an input on the
> IC, but the main ground - the one the coil current flows through - is
> the one shown in the lower right corner of the ignitor; the metal body
> of the ignitor itself. The current from pin 4 is undoubtedly in the
> range of 1 ma.
>
> Mike
>
>
>

Yes,the ECU signal is a normally HI,LO(ground)-to-enable signal.

Thanks!

--
Jim Yanik
jyanik
at
kua.net

Jim Yanik wrote:
>
> Randolph > wrote in :

> > See
> > http://www.st.com/stonline/books/ascii/docs/5288.htm for details. The
> > data sheet is at http://www.st.com/stonline/books/pdf/docs/5288.pdf. The
> > data sheet shows the diode between emitter and collector.
>
> The diode is INTERNAL to the transistor package.
> Probably on the same substrate as the xstr.

Yes, that is what I meant, and that is what the data sheet shows.

> > The IC in the photo looks like it has part number U2226B, and a good
> > guess is that the TFK in the first line stand for Telefunken, a German
> > semiconductor manufacturer later renamed TEMIC and eventually bought by
> > Vishay. I have not found any data sheet for the U2226B, but I believe it
> > is an opto-coupler.
> >
>
> I found ICs that were specifically designed for ignition control and
> driving the Darlingtons,but none with the same pin count of the IC
> pictured,nor any similarity to its part number.
> I do not believe it's an optocoupler,but a full control IC.Probably with
> circuitry to square up(shape) the drive pulse,and provide enough drive
> current,and IIRC,the ICs monitored and regulated coil current.(that would
> enable faster switching)

I did some more digging, and you are right, it is not an opto-coupler.
It is indeed a chip for controlling ignition coils. It is made by
Telefunken / TEMIC, and they had a family of 3: U2225B is used when the
input is from an inductive sensor, U2226B is intended for use with a
microcontroller / microprocessor and U2227B is used when the chip is
connected directly to an optical sensor. I have not had any luck finding
the data sheet for this part.

Jim Yanik .> wrote in
:


<snip>

>> That was how Jim got into the semantic trap to start with. The ECU
>> supplies a low current ground to pin 4, which grounds an input on the
>> IC, but the main ground - the one the coil current flows through - is
>> the one shown in the lower right corner of the ignitor; the metal body
>> of the ignitor itself. The current from pin 4 is undoubtedly in the
>> range of 1 ma.
>>
>> Mike
>>
>>
>>
>
> Yes,the ECU signal is a normally HI,LO(ground)-to-enable signal.
>


I've removed the innards of the igniter from the graphics and will add that
body round later on, changing the yellow and orange lines around to suit.
http://www.tegger.com/hondafaq/ignit...ion/index.html

Since the workings are far more detailed than I had originally imagined, I
will leave the igniter as a "here be dragons" blank box until somebody else
decides to supply a correct schematic for me to copy.

Thanks very much to all.

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/