Re: Ignition updates to the Unofficial FAQ
 

Jim Yanik <jyanik@abuse.gov.> wrote in
news:Xns96677D9AC821Bjyanikkuanet@129.250.170.84:


> I looked up the Darlington transistor that is depicted on the Honda
> igniter,and it has an internal diode to shunt the flyback voltage around
> it,to protect the Darlington.
>


Got a URL or a pic? I'd like to add that diode.

The pics I found showed resistors, but no diodes.

--
TeGGeR®

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

Re: Ignition updates to the Unofficial FAQ
 

TeGGeR® wrote:
> jim beam <nospam@example.net> wrote in
> news:qtOdnaMXMZGfdwbfRVn-3w@speakeasy.net:
>
>
>
>>i too was under the impression that the igniter handled dwell because
>>i know that happens with some other ignitions, but it seems that with
>>the honda, all that's taken care of by the ecu. #4 is the for the
>>ecu's output signal. the igniter just switches as soon as it gets
>>signal.
>>
>>but that said, i do have the gear to test that properly this time...
>>i have a spare working igniter - i'll do some more homework.
>
>
>
> That would really be appreciated, thanks.
>
>
probably not for a couple of weekends.

as a footnote to the condenser replacement, as i said before, both the
failed condenser & the condenserless crx distributors produced no r.f.
interference on the car stereo. but, if i was on the [hands free] cell
in the car, people always used to complain about static, even though i
couldn't hear any myself. tonight, [shows how bad it used to be that
i'd not bothered with the cell in the car for this long] i had to make a
call & i'm told it was completely clear! so the condenser /does/ make a
difference, even if the car stereo itself is sufficiently well filtered
to not be susceptible. this totally confirms kevin's rise rate explanation.

Re: Ignition updates to the Unofficial FAQ
 

TeGGeR® wrote:
> jim beam <nospam@example.net> wrote in
> news:qtOdnaMXMZGfdwbfRVn-3w@speakeasy.net:
>
>
>
>>i too was under the impression that the igniter handled dwell because
>>i know that happens with some other ignitions, but it seems that with
>>the honda, all that's taken care of by the ecu. #4 is the for the
>>ecu's output signal. the igniter just switches as soon as it gets
>>signal.
>>
>>but that said, i do have the gear to test that properly this time...
>>i have a spare working igniter - i'll do some more homework.
>
>
>
> That would really be appreciated, thanks.
>
>
probably not for a couple of weekends.

as a footnote to the condenser replacement, as i said before, both the
failed condenser & the condenserless crx distributors produced no r.f.
interference on the car stereo. but, if i was on the [hands free] cell
in the car, people always used to complain about static, even though i
couldn't hear any myself. tonight, [shows how bad it used to be that
i'd not bothered with the cell in the car for this long] i had to make a
call & i'm told it was completely clear! so the condenser /does/ make a
difference, even if the car stereo itself is sufficiently well filtered
to not be susceptible. this totally confirms kevin's rise rate explanation.

Re: Ignition updates to the Unofficial FAQ
 

In article <K5OdndxBgIYYgwDfRVn-qg@speakeasy.net>,
jim beam <nospam@example.net> wrote:

> TeGGeR® wrote:
> > jim beam <nospam@example.net> wrote in
> > news:qtOdnaMXMZGfdwbfRVn-3w@speakeasy.net:
> >
> >
> >
> >>i too was under the impression that the igniter handled dwell because
> >>i know that happens with some other ignitions, but it seems that with
> >>the honda, all that's taken care of by the ecu. #4 is the for the
> >>ecu's output signal. the igniter just switches as soon as it gets
> >>signal.
> >>
> >>but that said, i do have the gear to test that properly this time...
> >>i have a spare working igniter - i'll do some more homework.
> >
> >
> >
> > That would really be appreciated, thanks.
> >
> >
> probably not for a couple of weekends.
>
> as a footnote to the condenser replacement, as i said before, both the
> failed condenser & the condenserless crx distributors produced no r.f.
> interference on the car stereo. but, if i was on the [hands free] cell
> in the car, people always used to complain about static, even though i
> couldn't hear any myself. tonight, [shows how bad it used to be that
> i'd not bothered with the cell in the car for this long] i had to make a
> call & i'm told it was completely clear! so the condenser /does/ make a
> difference, even if the car stereo itself is sufficiently well filtered
> to not be susceptible. this totally confirms kevin's rise rate explanation.

Cellphones operate at frequencies hundreds of times higher than the rise
rate of the primary coil. What probably happened is that the rise rate
was faster than the transistor could turn off. In some cases you can
induce crazy RF oscillations if a digital circuit is forced into an
analog mode. That kind of oscillation roasts a transistor in a hurry
too.

The radio noise I mentioned is in cars like the older Toyotas where
there was a long meandering wire between the primary coil and the ECU
and tach. The 350V ignition pulses bled into everything. Aftermarket
component stereo equipment needed braided shields over the interconnects.

Re: Ignition updates to the Unofficial FAQ
 

In article <K5OdndxBgIYYgwDfRVn-qg@speakeasy.net>,
jim beam <nospam@example.net> wrote:

> TeGGeR® wrote:
> > jim beam <nospam@example.net> wrote in
> > news:qtOdnaMXMZGfdwbfRVn-3w@speakeasy.net:
> >
> >
> >
> >>i too was under the impression that the igniter handled dwell because
> >>i know that happens with some other ignitions, but it seems that with
> >>the honda, all that's taken care of by the ecu. #4 is the for the
> >>ecu's output signal. the igniter just switches as soon as it gets
> >>signal.
> >>
> >>but that said, i do have the gear to test that properly this time...
> >>i have a spare working igniter - i'll do some more homework.
> >
> >
> >
> > That would really be appreciated, thanks.
> >
> >
> probably not for a couple of weekends.
>
> as a footnote to the condenser replacement, as i said before, both the
> failed condenser & the condenserless crx distributors produced no r.f.
> interference on the car stereo. but, if i was on the [hands free] cell
> in the car, people always used to complain about static, even though i
> couldn't hear any myself. tonight, [shows how bad it used to be that
> i'd not bothered with the cell in the car for this long] i had to make a
> call & i'm told it was completely clear! so the condenser /does/ make a
> difference, even if the car stereo itself is sufficiently well filtered
> to not be susceptible. this totally confirms kevin's rise rate explanation.

Cellphones operate at frequencies hundreds of times higher than the rise
rate of the primary coil. What probably happened is that the rise rate
was faster than the transistor could turn off. In some cases you can
induce crazy RF oscillations if a digital circuit is forced into an
analog mode. That kind of oscillation roasts a transistor in a hurry
too.

The radio noise I mentioned is in cars like the older Toyotas where
there was a long meandering wire between the primary coil and the ECU
and tach. The 350V ignition pulses bled into everything. Aftermarket
component stereo equipment needed braided shields over the interconnects.

Re: Ignition updates to the Unofficial FAQ
 

"TeGGeR®" wrote:
>
> Got a URL or a pic? I'd like to add that diode.
>
> The pics I found showed resistors, but no diodes.

I have looked long and hard at the photos of the ignitor. The darlington
device is definitely from STM (http:/www.stm.com). The part number is
hard to decipher, but I am quite certain the first line of the part
number is BUxy41. I can't for the life of me see if "x" is actually a
character or just picture noise. The "y" looks like an "8" or a "9". The
second line of the part number almost certainly is "ZT". This is
consistent with "BU941ZT", which is an actual STM part number with a
package type like the one in the ignitor photo. The description is "HIGH
VOLTAGE IGNITION COIL DRIVER NPN POWER TRANSISTOR". 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 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.

Re: Ignition updates to the Unofficial FAQ
 

"TeGGeR®" wrote:
>
> Got a URL or a pic? I'd like to add that diode.
>
> The pics I found showed resistors, but no diodes.

I have looked long and hard at the photos of the ignitor. The darlington
device is definitely from STM (http:/www.stm.com). The part number is
hard to decipher, but I am quite certain the first line of the part
number is BUxy41. I can't for the life of me see if "x" is actually a
character or just picture noise. The "y" looks like an "8" or a "9". The
second line of the part number almost certainly is "ZT". This is
consistent with "BU941ZT", which is an actual STM part number with a
package type like the one in the ignitor photo. The description is "HIGH
VOLTAGE IGNITION COIL DRIVER NPN POWER TRANSISTOR". 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 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.

Re: Ignition updates to the Unofficial FAQ
 

Here are oscilloscope traces of an ignition coil with and without a
capacitor:

http://www.pixelmemory.us/Photos/Nerd/flyback/

Re: Ignition updates to the Unofficial FAQ
 

Here are oscilloscope traces of an ignition coil with and without a
capacitor:

http://www.pixelmemory.us/Photos/Nerd/flyback/

Re: Ignition updates to the Unofficial FAQ
 

Kevin McMurtrie wrote:
> Here are oscilloscope traces of an ignition coil with and without a
> capacitor:
>
> http://www.pixelmemory.us/Photos/Nerd/flyback/

awesome! that one without capacitor is /real/ ugly...

Re: Ignition updates to the Unofficial FAQ
 

Kevin McMurtrie wrote:
> Here are oscilloscope traces of an ignition coil with and without a
> capacitor:
>
> http://www.pixelmemory.us/Photos/Nerd/flyback/

awesome! that one without capacitor is /real/ ugly...

Re: Ignition updates to the Unofficial FAQ
 

In rec.autos.makers.honda jim beam <nospam@example.net> wrote:
> Kevin McMurtrie wrote:
>> Here are oscilloscope traces of an ignition coil with and without a
>> capacitor:
>>
>> http://www.pixelmemory.us/Photos/Nerd/flyback/

> awesome! that one without capacitor is /real/ ugly...

It reminds me of my Mazda rotary with points. I could see the dwell begin
to take up too much time as the RPM got higher.

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5

Re: Ignition updates to the Unofficial FAQ
 

In rec.autos.makers.honda jim beam <nospam@example.net> wrote:
> Kevin McMurtrie wrote:
>> Here are oscilloscope traces of an ignition coil with and without a
>> capacitor:
>>
>> http://www.pixelmemory.us/Photos/Nerd/flyback/

> awesome! that one without capacitor is /real/ ugly...

It reminds me of my Mazda rotary with points. I could see the dwell begin
to take up too much time as the RPM got higher.

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5

Re: Ignition updates to the Unofficial FAQ
 

Randolph <trash@junkmail.com> wrote in news:429D4577.2B7930FB@junkmail.com:

>
> "TeGGeR®" wrote:
>>
>> Got a URL or a pic? I'd like to add that diode.
>>
>> The pics I found showed resistors, but no diodes.
>
> I have looked long and hard at the photos of the ignitor. The darlington
> device is definitely from STM (http:/www.stm.com). The part number is
> hard to decipher, but I am quite certain the first line of the part
> number is BUxy41. I can't for the life of me see if "x" is actually a
> character or just picture noise. The "y" looks like an "8" or a "9". The
> second line of the part number almost certainly is "ZT". This is
> consistent with "BU941ZT", which is an actual STM part number with a
> package type like the one in the ignitor photo. The description is "HIGH
> VOLTAGE IGNITION COIL DRIVER NPN POWER TRANSISTOR". 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.
>
> 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)

--
Jim Yanik
jyanik
at
kua.net

Re: Ignition updates to the Unofficial FAQ
 

Randolph <trash@junkmail.com> wrote in news:429D4577.2B7930FB@junkmail.com:

>
> "TeGGeR®" wrote:
>>
>> Got a URL or a pic? I'd like to add that diode.
>>
>> The pics I found showed resistors, but no diodes.
>
> I have looked long and hard at the photos of the ignitor. The darlington
> device is definitely from STM (http:/www.stm.com). The part number is
> hard to decipher, but I am quite certain the first line of the part
> number is BUxy41. I can't for the life of me see if "x" is actually a
> character or just picture noise. The "y" looks like an "8" or a "9". The
> second line of the part number almost certainly is "ZT". This is
> consistent with "BU941ZT", which is an actual STM part number with a
> package type like the one in the ignitor photo. The description is "HIGH
> VOLTAGE IGNITION COIL DRIVER NPN POWER TRANSISTOR". 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.
>
> 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)

--
Jim Yanik
jyanik
at
kua.net