Ignition updates to the Unofficial FAQ

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TeGGeR®

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May 28, 2005, 12:25:21 AM5/28/05
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After a long passage of time and much dithering, I've finally finished two
big updates.

1) New section on igniter function
http://www.tegger.com/hondafaq/igniter-operation/howworks.html

2) Coil failure
http://www.tegger.com/hondafaq/startproblems.html#badcoil

Any critical advice is welcome. I'm not an electronics engineer, so there
are surely mistakes somewhere.

--
TeGGeR®

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

Remco

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May 28, 2005, 7:05:49 AM5/28/05
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TeGGeR® wrote:
> After a long passage of time and much dithering, I've finally finished two
> big updates.
>
> 1) New section on igniter function
> http://www.tegger.com/hondafaq/igniter-operation/howworks.html
>
> 2) Coil failure
> http://www.tegger.com/hondafaq/startproblems.html#badcoil
>
> Any critical advice is welcome. I'm not an electronics engineer, so there
> are surely mistakes somewhere.

Good job, John. Thanks!

TeGGeR®

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May 28, 2005, 8:28:09 AM5/28/05
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"Remco" <why...@yahoo.com> wrote in
news:1117278349.3...@g44g2000cwa.googlegroups.com:


Thanks.

Thanks are also owed to all those (including you) who helped by supplying
much valuable information.

Jason

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May 28, 2005, 1:25:10 PM5/28/05
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In article <Xns966440B...@207.14.113.17>, "TeGGeR®"
<teg...@tegger.c0m> wrote:

> After a long passage of time and much dithering, I've finally finished two
> big updates.
>
> 1) New section on igniter function
> http://www.tegger.com/hondafaq/igniter-operation/howworks.html
>
> 2) Coil failure
> http://www.tegger.com/hondafaq/startproblems.html#badcoil
>
> Any critical advice is welcome. I'm not an electronics engineer, so there
> are surely mistakes somewhere.

Tegger,
Thanks again for your help. I just wanted to let you know that I received
a letter from Honda and the title of the recall notice was:
Ignition key is removable with the shift lever out of Park

I took my Honda to the local Honda dealership and they installed the
following as per the service report:
1 06351-S84-000 KIT, LEVER (A)

I don't know whether the first number 1 is part of the part number or
means that only one kit was installed. I hope this helps. I have not yet
had a chance to revisit your web site.

--
NEWSGROUP SUBSCRIBERS MOTTO
We respect those subscribers that ask for advice or provide advice.
We do NOT respect the subscribers that enjoy criticizing people.

Kevin McMurtrie

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May 30, 2005, 8:16:01 PM5/30/05
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In article <Xns966440B...@207.14.113.17>,
"TeGGeR®" <teg...@tegger.c0m> wrote:

> After a long passage of time and much dithering, I've finally finished two
> big updates.
>
> 1) New section on igniter function
> http://www.tegger.com/hondafaq/igniter-operation/howworks.html
>
> 2) Coil failure
> http://www.tegger.com/hondafaq/startproblems.html#badcoil
>
> Any critical advice is welcome. I'm not an electronics engineer, so there
> are surely mistakes somewhere.

A little adjustment to the graphics:

The darlington pair is the switch. Pin 3 would be the pulses from the
ECU or magnetic pickup. The tach connects either to the primary winding
(which makes radio interference) or to whatever drives the transistors.

And yes, the ignitor gets flyback voltage too. Some electronic ignition
systems still need the condenser because the flyback voltage on the
primary side otherwise rises extremely rapidly. It can rise faster than
some high voltage transistors can turn off and it can even rise before
the spark plug discharges the energy.

jim beam

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May 30, 2005, 8:31:34 PM5/30/05
to

interesting. i had 2 igniters fail inside a year on my 89 civic &
subsequently discovered that the condenser had failed. presumably,
excess flyback was responsible. but, my 91 crx has no condenser at all,
from factory. what's up with that? works fine, no r.f problems. both
have the same igniter. any thoughts?

Kevin McMurtrie

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May 30, 2005, 10:20:12 PM5/30/05
to
In article <k6GdnTKjuPj...@speakeasy.net>,
jim beam <nos...@example.net> wrote:

The coil might have an internal condenser or a small shorted winding.
An oscilloscope on the primary coil would show you what's going on.

I'm doing this from memory so the shape might be a little off:


v- Spark plug discharge

|
|
|#
|##
| |
| |
| |
--- | --------------------------
-----------

^ ^ ^ flyback
| charge
open circuit


Without a condenser, the initial spike is much higher and it rises so
steeply that it might not produce a visible trace on the oscilloscope.

|


.


.#
##
|
|
|
--- --------------------------
-----------

jim beam

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May 30, 2005, 10:55:49 PM5/30/05
to

makes sense. i have an old scope so i can check between the two. thanks!

TeGGeR®

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May 30, 2005, 11:30:23 PM5/30/05
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Kevin McMurtrie <mcmu...@dslextreme.com> wrote in
news:mcmurtri-579156...@corp-radius.supernews.com:

> In article <Xns966440B...@207.14.113.17>,
> "TeGGeR®" <teg...@tegger.c0m> wrote:
>
>> After a long passage of time and much dithering, I've finally
>> finished two big updates.
>>
>> 1) New section on igniter function
>> http://www.tegger.com/hondafaq/igniter-operation/howworks.html
>>
>> 2) Coil failure
>> http://www.tegger.com/hondafaq/startproblems.html#badcoil
>>
>> Any critical advice is welcome. I'm not an electronics engineer, so
>> there are surely mistakes somewhere.
>
> A little adjustment to the graphics:
>
> The darlington pair is the switch. Pin 3 would be the pulses from the
> ECU or magnetic pickup. The tach connects either to the primary
> winding (which makes radio interference) or to whatever drives the
> transistors.


Take a look at this, from Graham W.
http://www.tegger.com/hondafaq/misc/rov-ign.jpg


>
> And yes, the ignitor gets flyback voltage too. Some electronic
> ignition systems still need the condenser because the flyback voltage
> on the primary side otherwise rises extremely rapidly. It can rise
> faster than some high voltage transistors can turn off and it can even
> rise before the spark plug discharges the energy.


So how would I show that in the graphic? If there's a cap somewhere to
blunt the flyback, I'd like to have that shown.

Kevin McMurtrie

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May 31, 2005, 12:20:42 AM5/31/05
to
In article <Xns9666EF23...@207.14.113.17>,
"TeGGeR®" <teg...@tegger.c0m> wrote:

> Kevin McMurtrie <mcmu...@dslextreme.com> wrote in
> news:mcmurtri-579156...@corp-radius.supernews.com:
>
> > In article <Xns966440B...@207.14.113.17>,
> > "TeGGeR®" <teg...@tegger.c0m> wrote:
> >
> >> After a long passage of time and much dithering, I've finally
> >> finished two big updates.
> >>
> >> 1) New section on igniter function
> >> http://www.tegger.com/hondafaq/igniter-operation/howworks.html
> >>
> >> 2) Coil failure
> >> http://www.tegger.com/hondafaq/startproblems.html#badcoil
> >>
> >> Any critical advice is welcome. I'm not an electronics engineer, so
> >> there are surely mistakes somewhere.
> >
> > A little adjustment to the graphics:
> >
> > The darlington pair is the switch. Pin 3 would be the pulses from the
> > ECU or magnetic pickup. The tach connects either to the primary
> > winding (which makes radio interference) or to whatever drives the
> > transistors.
>
>
> Take a look at this, from Graham W.
> http://www.tegger.com/hondafaq/misc/rov-ign.jpg
>

There's a lot more in the Ignition Control Module than a darlington
pair. As I see it:

1: Tach output
2: Coil output
3: +12V
4: TDC pickup
Case: GND

The TDC sensor produces a curved waveform. Integrating the form
(high-pass) can produce the advanced timing needed for dwell.


> >
> > And yes, the ignitor gets flyback voltage too. Some electronic
> > ignition systems still need the condenser because the flyback voltage
> > on the primary side otherwise rises extremely rapidly. It can rise
> > faster than some high voltage transistors can turn off and it can even
> > rise before the spark plug discharges the energy.
>
>
> So how would I show that in the graphic? If there's a cap somewhere to
> blunt the flyback, I'd like to have that shown.

Maybe Jim Beam can take a photo of his o-scope. My new Honda has a coil
on top of each spark plug so I'm not sure I can tap into the primary
coil. I have a circuit that drives coils but it's not quite the same as
a car ignition. Want a picture of that trace?

jim beam

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May 31, 2005, 12:37:21 AM5/31/05
to

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.

TeGGeR®

unread,
May 31, 2005, 7:14:23 AM5/31/05
to
Kevin McMurtrie <mcmu...@dslextreme.com> wrote in news:mcmurtri-
8690B7.212...@corp-radius.supernews.com:


> There's a lot more in the Ignition Control Module than a darlington
> pair.


True. And I see that in these photos.
http://www.gcw.org.uk/rover/igniter.htm

Here's another page to critique:
http://www.tegger.com/hondafaq/igniter-operation/badigniter.html


> As I see it:
>
> 1: Tach output


It's there.


> 2: Coil output


It's there


> 3: +12V


It's there


> 4: TDC pickup

According to the diagrams I'm seeing, such as
http://www.tegger.com/hondafaq/misc/rov-ign.jpg
#4 goes directly to the ECU. I think the TDC pickup goes directly to the
ECU as well.


> Case: GND


Yes, but not really nesessary to show in this context.



> The TDC sensor produces a curved waveform. Integrating the form
> (high-pass) can produce the advanced timing needed for dwell.
>
>
>> >
>> > And yes, the ignitor gets flyback voltage too. Some electronic
>> > ignition systems still need the condenser because the flyback voltage
>> > on the primary side otherwise rises extremely rapidly. It can rise
>> > faster than some high voltage transistors can turn off and it can even
>> > rise before the spark plug discharges the energy.
>>
>>
>> So how would I show that in the graphic? If there's a cap somewhere to
>> blunt the flyback, I'd like to have that shown.
>
> Maybe Jim Beam can take a photo of his o-scope. My new Honda has a coil
> on top of each spark plug so I'm not sure I can tap into the primary
> coil. I have a circuit that drives coils but it's not quite the same as
> a car ignition. Want a picture of that trace?
>


Sure! Thanks.

TeGGeR®

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May 31, 2005, 7:16:23 AM5/31/05
to
jim beam <nos...@example.net> wrote in
news:qtOdnaMXMZG...@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.

jim beam

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May 31, 2005, 9:02:01 AM5/31/05
to
TeGGeRŽ wrote:
> Kevin McMurtrie <mcmu...@dslextreme.com> wrote in news:mcmurtri-
> 8690B7.212...@corp-radius.supernews.com:
>
>
>
>>There's a lot more in the Ignition Control Module than a darlington
>>pair.
>
>
>
> True. And I see that in these photos.
> http://www.gcw.org.uk/rover/igniter.htm
>
> Here's another page to critique:
> http://www.tegger.com/hondafaq/igniter-operation/badigniter.html

looks like a good summary. obviously, as graham's pics show, there's
more to the igiter than the darlington, but what you show is a good
interpretation of the result. it's also worth mentioning that in both
my igniter failures, there's been no code. terminal 4 is behaving as
per normal, [hence no ecu] but the igniter output is failed hard "on"
and switching the input makes no difference to output.

i think it's also worth showing the condenser & mentioning its role too.
it's a $25 part & a pita to replace, but mine failed with a near dead
short so even before the igniter failed, my car had been chronically
weak & the exhaust way sooty because there was no strenght to the spark.

Jim Yanik

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May 31, 2005, 12:22:13 PM5/31/05
to
Kevin McMurtrie <mcmu...@dslextreme.com> wrote in
news:mcmurtri-579156...@corp-radius.supernews.com:

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.

--
Jim Yanik
jyanik
at
kua.net

TeGGeR®

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May 31, 2005, 10:17:25 PM5/31/05
to
Jim Yanik <jya...@abuse.gov.> wrote in
news:Xns96677D9AC82...@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.

jim beam

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May 31, 2005, 10:33:41 PM5/31/05
to
TeGGeRŽ wrote:
> jim beam <nos...@example.net> wrote in
> news:qtOdnaMXMZG...@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.

Kevin McMurtrie

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Jun 1, 2005, 1:02:07 AM6/1/05
to
In article <K5OdndxBgIY...@speakeasy.net>,
jim beam <nos...@example.net> wrote:

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.

Randolph

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Jun 1, 2005, 1:18:50 AM6/1/05
to

"TeGGeRŽ" 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.

Kevin McMurtrie

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Jun 1, 2005, 2:24:17 AM6/1/05
to
Here are oscilloscope traces of an ignition coil with and without a
capacitor:

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

jim beam

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Jun 1, 2005, 9:09:22 AM6/1/05
to

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

do...@xrexxignit.usenet.us.com

unread,
Jun 1, 2005, 10:57:18 AM6/1/05
to

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

Jim Yanik

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Jun 1, 2005, 11:37:37 AM6/1/05
to
Randolph <tr...@junkmail.com> wrote in news:429D4577...@junkmail.com:

>
> "TeGGeRŽ" 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)

TeGGeR®

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Jun 1, 2005, 11:31:03 PM6/1/05
to

> The


> data sheet shows the diode between emitter and collector.


So then it wouldn't make much sense to try and show it.

Randolph, I'm having trouble understanding the current path through the
transistor. I found this page:
http://nobelprize.org/physics/educational/transistor/function/thegame.html

It helps me understand more, but I don't get which way the current goes
through the base electrode. I have a suspicion that my diagrams show the
current going the wrong way through the transistor.
http://www.tegger.com/hondafaq/igniter-operation/index.html

TeGGeR®

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Jun 1, 2005, 11:36:34 PM6/1/05
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do...@XReXXIgnit.usenet.us.com wrote in news:d7kice$pvn$2...@blue.rahul.net:

> In rec.autos.makers.honda jim beam <nos...@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 had a '74 RX-4 Coupe!


> I could see the dwell
> begin to take up too much time as the RPM got higher.
>


You guys...I swear...

If the subject gets any more high-flown, it's gonna head for outer space.

This is excellent info. Now I've got to make another page: More detail for
the Electronics Whiz.

Jim Yanik

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Jun 2, 2005, 9:47:18 AM6/2/05
to
"TeGGeRŽ" <teg...@tegger.c0m> wrote in
news:Xns9668EF41...@207.14.113.17:

There's two current paths;the B-E path and the C-E path(main path).
Current flows the opposite direction of the emitter arrow,for both base and
collector currents.

TeGGeR®

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Jun 2, 2005, 3:22:57 PM6/2/05
to
Jim Yanik <jya...@abuse.gov.> wrote in
news:Xns966963506AD...@129.250.170.86:

> "TeGGeR®" <teg...@tegger.c0m> wrote in


> news:Xns9668EF41...@207.14.113.17:
>
>> Randolph <tr...@junkmail.com> wrote in
>> news:429D4577...@junkmail.com:
>>
>>> The
>>> data sheet shows the diode between emitter and collector.
>>
>>
>> So then it wouldn't make much sense to try and show it.
>>
>> Randolph, I'm having trouble understanding the current path through
>> the transistor. I found this page:
>> http://nobelprize.org/physics/educational/transistor/function/thegame.

>> h tml

>>
>> It helps me understand more, but I don't get which way the current
>> goes through the base electrode. I have a suspicion that my diagrams
>> show the current going the wrong way through the transistor.
>> http://www.tegger.com/hondafaq/igniter-operation/index.html
>>
>>
>>
>
> There's two current paths;the B-E path and the C-E path(main path).
> Current flows the opposite direction of the emitter arrow,for both
> base and collector currents.
>


I'm having trouble getting my mind around this.

I am aware that "flow" is _commonly_ considered to be from the positive to
negative terminals of the battery, but the electrons themselves go in the
OTHER direction.

http://www.tegger.com/hondafaq/igniter-operation/index.html
http://www.tegger.com/hondafaq/igniter-operation/badigniter.html
On these two pages, is the current flow through the transistors correctly
depicted? Nobody has answered that question yet.

Jim Yanik

unread,
Jun 2, 2005, 6:51:30 PM6/2/05
to
"TeGGeRŽ" <teg...@tegger.c0m> wrote in
news:Xns96699C7F...@207.14.113.17:

>> "TeGGeRŽ" <teg...@tegger.c0m> wrote in


>> news:Xns9668EF41...@207.14.113.17:
>>
>>> Randolph <tr...@junkmail.com> wrote in
>>> news:429D4577...@junkmail.com:
>>>
>>>> The
>>>> data sheet shows the diode between emitter and collector.
>>>
>>>
>>> So then it wouldn't make much sense to try and show it.
>>>
>>> Randolph, I'm having trouble understanding the current path through
>>> the transistor. I found this page:
>>> http://nobelprize.org/physics/educational/transistor/function/thegame

>>> . h tml

>>>
>>> It helps me understand more, but I don't get which way the current
>>> goes through the base electrode. I have a suspicion that my diagrams
>>> show the current going the wrong way through the transistor.
>>> http://www.tegger.com/hondafaq/igniter-operation/index.html
>>>
>>>
>>>
>>
>> There's two current paths;the B-E path and the C-E path(main path).
>> Current flows the opposite direction of the emitter arrow,for both
>> base and collector currents.
>>
>
>
> I'm having trouble getting my mind around this.
>
> I am aware that "flow" is _commonly_ considered to be from the
> positive to negative terminals of the battery, but the electrons
> themselves go in the OTHER direction.
>
> http://www.tegger.com/hondafaq/igniter-operation/index.html
> http://www.tegger.com/hondafaq/igniter-operation/badigniter.html
> On these two pages, is the current flow through the transistors
> correctly depicted? Nobody has answered that question yet.
>

The electrons are what's doing the moving,and they flow from neg to pos.

TeGGeR®

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Jun 2, 2005, 9:11:23 PM6/2/05
to
Jim Yanik <jya...@abuse.gov.> wrote in
news:Xns9669BF9265B...@129.250.170.83:


>>
>
> The electrons are what's doing the moving,and they flow from neg to pos.
>


The electrons flow from POSITIVE TO NEGATIVE. The electrons go from where
they are (-) to where they're not: The "holes" (+).
http://nobelprize.org/physics/educational/transistor/function/forward.html

It's the actual everyday signal that's commonly perceived to go from
negative to positive.

But we have THREE paths in a transistor ("transfer resistor"). For a non-
techie, this is non-intuitive. I do not get how TWO terminals can have
THREE paths.

Please try to understand that I am not trying to be difficult, but that
this is not at all making sense to me.

I am hoping that someone, somewhere, will post with an explanation that
makes sense to my mind. In my professional life I have taught and trained
many, many individuals, and most have had certain things that just would
not "click" until the information was presented a certain way. I am seeking
that way, and I will persist until I find it. This is driving me crazy.

This graphic:
http://nobelprize.org/physics/educational/transistor/function/amplification
.html
(all on one line; copy-and-paste as necessary)
shows the signal path from base electrode to collector.

This one:
http://nobelprize.org/physics/educational/transistor/function/pointsymbol.h
tml
(again, all on one line)
appears to show the path from emitter to collector.

I do not get this and I am trying madly to understand. Graham W would be
able to correct me in an instant. He has been the most persnicketly
critical observer and the most productive from my point of view. Graham,
where aaaaaare you?...

Graham was the ONLY one to suggest alterations to the Main Relay function
graphics. Graham was the ONLY one to inform me of certain HTML errors, the
correction of which make it easier for browsers to display the intended
information.

Ah, but wait. I just thought of something: alt.electronics. Back soon...

TeGGeR®

unread,
Jun 2, 2005, 9:22:58 PM6/2/05
to
"TeGGeR®" <teg...@tegger.c0m> wrote in
news:Xns9669D79...@207.14.113.17:


> Ah, but wait. I just thought of something: alt.electronics. Back
> soon...
>


Just checked message counts.
sci.electronics.misc
sci.electronics.repair
and
alt.home.repair
seem better choices, in case anyone wants to follow along...

I'm hoping to elicit responses from somebody like Sam Goldwasser.

Michael Pardee

unread,
Jun 2, 2005, 9:35:17 PM6/2/05
to
"TeGGeRŽ" <teg...@tegger.c0m> wrote in message
news:Xns9669D79...@207.14.113.17...
> The electrons flow from POSITIVE TO NEGATIVE. The electrons go from where
> they are (-) to where they're not: The "holes" (+).
> http://nobelprize.org/physics/educational/transistor/function/forward.html
>
There is a big part of the confusion - electrons flow from [-] to [+].

The entire "hole" thing never helped me, either. I got a lot farther when I
started thinking of where the "positives" flowed, because both vacuum tubes
(which were still common when I was learning electronics) and NPN
transistors (which are the most common now but least common originally, both
for technical reasons) use negative ground. Trying to follow electron flow
distorts the idea of the ground, while thinking of "positives" flowing from
the power supply to ground worked great. (Also the "positives" flow in the
direction of the arrow on the emitter.)

For NPN transistors, here is the simple view. The emitter is grounded and
the collector has positive voltage applied to it. The transistor doesn't
conduct because the collector-base junction is reverse biased. Now positive
voltage is applied to the base. Below about 0.7 volts on the base nothing
much happens. As 0.7 volts is approached the base-emitter junction starts
drawing current, just like any other ordinary silicon diode. The
base-emitter current causes tens to hundreds of times that much current to
flow from the collector to emitter. As the base voltage rises to about 0.8
or 0.9 volts, the base-emitter current is so high that the collector current
can't go any higher - the voltage at the collector has dropped to only
0.1-0.2 volts, and the entire supply voltage (like the 12V battery) is
across whatever load is between the power supply and the collector. In the
ignition circuit, the collector has grounded the primary of the coil. This
condition is called "saturation" because increasing the base current doesn't
do anything to the collector any more.

It is important in switching circuits like the ignition to saturate the
transistor. If the collector voltage doesn't go very near ground, the
transistor has to dissipate the current times whatever voltage is left. If
the voltage is only twice the saturation voltage (say, 0.3 instead of 0.15)
the transistor has to dissipate twice the power.

Mike


Kevin McMurtrie

unread,
Jun 3, 2005, 1:24:11 AM6/3/05
to
In article <Xns96699C7F...@207.14.113.17>,
"TeGGeR®" <teg...@tegger.c0m> wrote:

Most materials have an electron flow, which goes from negative to
positive. I've heard that some materials can have a proton flow. Both
may exist in a vacuum.

Current flow arrows on diagrams go from positive to negative.

Bipolar transistors are current amplifiers. When a current flows
through the base-emitter diode junction, a stronger current is allowed
to flow from the collector to the emitter. The C-E junction is .2 to .4
volts when the B-E junction is saturated (~.65 V). The current gain for
a power transistor is usually 10 to 100. Darlington pairs have that
gain squared. Gains are not at all consistent so they're usually
specified as a range.

MOSFETs are tiny voltage controlled amplifiers. Absolutely zero static
current is required to turn them on or off; just the capacitance
current. Because of their infinite current gain, millions may be
paralleled on a single chip to satisfy any current load. Their voltage
gain is very low - a typical gate threshold voltage is 4V and a typical
gate saturation voltage is 10V. There's no voltage drop between the
source and drain, only resistance. High voltage capability makes each
MOSFET junction larger and dramatically increases resistance.

IGBTs are similar to bipolar transistors but with an insulated gate like
a MOSFET. They have the high voltage capacity of bipolars but need no
driving current like a MOSFET. They're very slow so they're usually
limited to controlling industrial motors. (Honda hybrid cars use them
for their motors.)

TeGGeR®

unread,
Jun 3, 2005, 8:34:49 AM6/3/05
to
Kevin McMurtrie <mcmu...@dslextreme.com> wrote in
news:mcmurtri-A3D31B...@corp-radius.supernews.com:

> In article <Xns96699C7F...@207.14.113.17>,
> "TeGGeR®" <teg...@tegger.c0m> wrote:
>

>> I'm having trouble getting my mind around this.
>>
>> I am aware that "flow" is _commonly_ considered to be from the
>> positive to negative terminals of the battery, but the electrons
>> themselves go in the OTHER direction.
>
> Most materials have an electron flow, which goes from negative to
> positive. I've heard that some materials can have a proton flow.
> Both may exist in a vacuum.
>
> Current flow arrows on diagrams go from positive to negative.
>
> Bipolar transistors are current amplifiers. When a current flows
> through the base-emitter diode junction, a stronger current is allowed
> to flow from the collector to the emitter.

So then my diagrams are correct. I assumed the base electrode to act as the
switch, turning power on and off between the collector and the emitter.

Thanks.

jim beam

unread,
Jun 3, 2005, 8:52:41 AM6/3/05
to

don't get no proton flow unless you're into nuclear chemistry. in
semiconductors, conduction is by way of negative electrons & positive
"holes". you /can/ have [positive] ions move in the semiconductor
lattice, but they are not a part of the primary conduction mechanism &
result in mass transport & therefore degradation of the semiconductor -
they are not a proton thing.

Jim Yanik

unread,
Jun 3, 2005, 11:01:04 AM6/3/05
to
"TeGGeRŽ" <teg...@tegger.c0m> wrote in
news:Xns9669D79...@207.14.113.17:

> Jim Yanik <jya...@abuse.gov.> wrote in
> news:Xns9669BF9265B...@129.250.170.83:
>
>
>>>
>>
>> The electrons are what's doing the moving,and they flow from neg to
>> pos.
>>
>
>
> The electrons flow from POSITIVE TO NEGATIVE. The electrons go from
> where they are (-) to where they're not: The "holes" (+).
> http://nobelprize.org/physics/educational/transistor/function/forward.h
> tml
>
> It's the actual everyday signal that's commonly perceived to go from
> negative to positive.
>
> But we have THREE paths in a transistor ("transfer resistor"). For a
> non- techie, this is non-intuitive. I do not get how TWO terminals can
> have THREE paths.

think of a Y water pipe.One arm of the Y is smaller than the other.But the
total water flow thru the bottom of the Y divides and part passes thru the
left arm and part thru the right arm.You can control how much water passes
thru the right arm by adjusting the flow thru the left arm.(but the water
pipe does not have any current gain)

>
> Please try to understand that I am not trying to be difficult, but
> that this is not at all making sense to me.
>
> I am hoping that someone, somewhere, will post with an explanation
> that makes sense to my mind. In my professional life I have taught and
> trained many, many individuals, and most have had certain things that
> just would not "click" until the information was presented a certain
> way. I am seeking that way, and I will persist until I find it. This
> is driving me crazy.
>
> This graphic:
> http://nobelprize.org/physics/educational/transistor/function/amplifica

> tion .html


> (all on one line; copy-and-paste as necessary)
> shows the signal path from base electrode to collector.
>
> This one:
> http://nobelprize.org/physics/educational/transistor/function/pointsymb

> ol.h tml


> (again, all on one line)
> appears to show the path from emitter to collector.
>
> I do not get this and I am trying madly to understand. Graham W would
> be able to correct me in an instant. He has been the most persnicketly
> critical observer and the most productive from my point of view.
> Graham, where aaaaaare you?...
>
> Graham was the ONLY one to suggest alterations to the Main Relay
> function graphics. Graham was the ONLY one to inform me of certain
> HTML errors, the correction of which make it easier for browsers to
> display the intended information.
>
> Ah, but wait. I just thought of something: alt.electronics. Back
> soon...
>

Just think of a vacuum tube;the cathode(negative terminal) is heated so it
will emit *electrons*,which are attracted to the positively charged anode
plate,thus;ELECTRON FLOW,from negative to positive.

TeGGeR®

unread,
Jun 3, 2005, 8:46:02 PM6/3/05
to
Jim Yanik <jya...@abuse.gov.> wrote in
news:Xns966A6FCED79...@129.250.170.86:


>
> think of a Y water pipe.One arm of the Y is smaller than the other.But
> the total water flow thru the bottom of the Y divides and part passes
> thru the left arm and part thru the right arm.You can control how much
> water passes thru the right arm by adjusting the flow thru the left
> arm.(but the water pipe does not have any current gain)


So then my drawings are NOT correct. I need to show the emitter (closest to
the coil) "switched off", and not the collector (farthest from the coil).
Right? Or does it matter since the effect is the same?

Michael Pardee

unread,
Jun 3, 2005, 9:28:04 PM6/3/05
to
"TeGGeR®" <teg...@tegger.c0m> wrote in message
news:Xns966AD347...@207.14.113.17...

The emitter is the neutral part of it, the part the collector gets switched
to.

Maybe the easiest way to think of it is as a relay, where the emitter is one
end of the winding and one of the contacts. The base is the other end of the
winding and the collector is the other normally open contact. When current
is run through the "winding" (from the base to the emitter) the collector
closes the circuit to the emitter.

There are a few technical details like polarity (the collector and base both
have to be positive with respect to the emitter) and the base resistance (so
low the current has to be limited by external resistance), but the operation
in an ignitor is just like a very fast relay. In other circuits it isn't
used as a relay, and the collector current is varied more proportionately to
the base current.

Mike


Jim Yanik

unread,
Jun 3, 2005, 9:16:11 PM6/3/05
to
"TeGGeRŽ" <teg...@tegger.c0m> wrote in
news:Xns966AD347...@207.14.113.17:

For a NPN transistor,the collector should go to the coil,and the emitter to
ground. The other end of the coil goes to +12V.
The internal diode shunts the back EMF around the transistor to
ground,protecting the transistor.


I just looked at your schematic,and it appears correct.except that terminal
3 of the Igniter module does not go straight to the Darlington base,it goes
to the IC that controls the Darlington.You need a rectangle indicating the
control IC between the Pin 3 and the Darlington base.Pin 1(tach drive)
probably goes to the control IC,too,certainly not to ground,Pin 4.

(the emitter of the Darlington probably goes to the control IC,too,then
thru a small value resistor[<1 ohm] for current monitoring by the IC,then
to ground.)

TeGGeR®

unread,
Jun 3, 2005, 10:29:32 PM6/3/05
to
Jim Yanik <jya...@abuse.gov.> wrote in
news:Xns966AD818247...@129.250.170.85:


>
> For a NPN transistor,the collector should go to the coil,and the
> emitter to ground. The other end of the coil goes to +12V.
> The internal diode shunts the back EMF around the transistor to
> ground,protecting the transistor.
>
>
> I just looked at your schematic,and it appears correct.except that
> terminal 3 of the Igniter module does not go straight to the
> Darlington base,it goes to the IC that controls the Darlington.You
> need a rectangle indicating the control IC between the Pin 3 and the
> Darlington base.Pin 1(tach drive) probably goes to the control
> IC,too,certainly not to ground,Pin 4.
>
> (the emitter of the Darlington probably goes to the control
> IC,too,then thru a small value resistor[<1 ohm] for current monitoring
> by the IC,then to ground.)
>


More information here than I've gotten yet. Thanks.

Jim Yanik

unread,
Jun 4, 2005, 11:10:07 AM6/4/05
to
"TeGGeRŽ" <teg...@tegger.c0m> wrote in
news:Xns966AE4D4...@207.14.113.17:

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.If the
ECU were to be the ground for the igniter,that would mean that the entire
coil current(several amps) would have to travel through the long wire from
igniter to ECU,and the ECU itself would have to switch that high current to
ground,which is the purpose of the igniter.

TeGGeR®

unread,
Jun 4, 2005, 11:37:13 AM6/4/05
to
Jim Yanik <jya...@abuse.gov.> wrote in
news:Xns966B71542D3...@129.250.170.84:


>
> 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 a the text immediately below the title.

> If the ECU were to be the ground for the igniter,that would mean
> that the entire coil current(several amps) would have to travel
> through the long wire from igniter to ECU,and the ECU itself would
> have to switch that high current to ground,which is the purpose of the
> igniter.
>


Then I'm still looking for a definitive answer.

Michael Pardee

unread,
Jun 4, 2005, 12:05:01 PM6/4/05
to
----- Original Message -----
From: "TeGGeR®" <teg...@tegger.c0m>
Newsgroups: rec.autos.makers.honda,alt.autos.acura,alt.autos.honda
Sent: Saturday, June 04, 2005 8:37 AM
Subject: Re: Ignition updates to the Unofficial FAQ


> Jim Yanik <jya...@abuse.gov.> wrote in
> news:Xns966B71542D3...@129.250.170.84:
>
>
>>
>> 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


Jim Yanik

unread,
Jun 4, 2005, 12:36:01 PM6/4/05
to
"Michael Pardee" <michae...@cybertrails.com> wrote in
news:qKSdnf1wB6O...@sedona.net:

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

Thanks!

Randolph

unread,
Jun 5, 2005, 2:03:36 PM6/5/05
to

Jim Yanik wrote:
>
> Randolph <tr...@junkmail.com> wrote in news:429D4577...@junkmail.com:

> > 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.

TeGGeR®

unread,
Jun 6, 2005, 8:34:15 AM6/6/05
to
Jim Yanik <jya...@abuse.gov.> wrote in
news:Xns966B7FE54E...@129.250.170.84:


<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/igniter-operation/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.

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