TeGGeR®

Kevin McMurtrie <mcmurtri@dslextreme.com> wrote in
news:mcmurtri-579156.17160130052005@corp-radius.supernews.com:

> In article <Xns966440B3E088tegger@207.14.113.17>,
> "TeGGeR®" <tegger@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/ignit.../howworks.html
>>
>> 2) Coil failure
>> http://www.tegger.com/hondafaq/start...s.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.

--
TeGGeR®

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

TeGGeR®

Kevin McMurtrie <mcmurtri@dslextreme.com> wrote in
news:mcmurtri-579156.17160130052005@corp-radius.supernews.com:

> In article <Xns966440B3E088tegger@207.14.113.17>,
> "TeGGeR®" <tegger@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/ignit.../howworks.html
>>
>> 2) Coil failure
>> http://www.tegger.com/hondafaq/start...s.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.

--
TeGGeR®

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

Kevin McMurtrie

In article <Xns9666EF231308Dtegger@207.14.113.17>,
"TeGGeR®" <tegger@tegger.c0m> wrote:

> Kevin McMurtrie <mcmurtri@dslextreme.com> wrote in
> news:mcmurtri-579156.17160130052005@corp-radius.supernews.com:
>
> > In article <Xns966440B3E088tegger@207.14.113.17>,
> > "TeGGeR®" <tegger@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/ignit.../howworks.html
> >>
> >> 2) Coil failure
> >> http://www.tegger.com/hondafaq/start...s.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?

Kevin McMurtrie

In article <Xns9666EF231308Dtegger@207.14.113.17>,
"TeGGeR®" <tegger@tegger.c0m> wrote:

> Kevin McMurtrie <mcmurtri@dslextreme.com> wrote in
> news:mcmurtri-579156.17160130052005@corp-radius.supernews.com:
>
> > In article <Xns966440B3E088tegger@207.14.113.17>,
> > "TeGGeR®" <tegger@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/ignit.../howworks.html
> >>
> >> 2) Coil failure
> >> http://www.tegger.com/hondafaq/start...s.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

Kevin McMurtrie wrote:
> In article <Xns9666EF231308Dtegger@207.14.113.17>,
> "TeGGeR®" <tegger@tegger.c0m> wrote:
>
>
>>Kevin McMurtrie <mcmurtri@dslextreme.com> wrote in
>>news:mcmurtri-579156.17160130052005@corp-radius.supernews.com:
>>
>>
>>>In article <Xns966440B3E088tegger@207.14.113.17>,
>>> "TeGGeR®" <tegger@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/ignit.../howworks.html
>>>>
>>>>2) Coil failure
>>>>http://www.tegger.com/hondafaq/start...s.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.

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.

>
>
>
>>>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

Kevin McMurtrie wrote:
> In article <Xns9666EF231308Dtegger@207.14.113.17>,
> "TeGGeR®" <tegger@tegger.c0m> wrote:
>
>
>>Kevin McMurtrie <mcmurtri@dslextreme.com> wrote in
>>news:mcmurtri-579156.17160130052005@corp-radius.supernews.com:
>>
>>
>>>In article <Xns966440B3E088tegger@207.14.113.17>,
>>> "TeGGeR®" <tegger@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/ignit.../howworks.html
>>>>
>>>>2) Coil failure
>>>>http://www.tegger.com/hondafaq/start...s.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.

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.

>
>
>
>>>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?

TeGGeR®

Kevin McMurtrie <mcmurtri@dslextreme.com> wrote in news:mcmurtri-
8690B7.21204230052005@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/ignit...adigniter.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®

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

TeGGeR®

Kevin McMurtrie <mcmurtri@dslextreme.com> wrote in news:mcmurtri-
8690B7.21204230052005@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/ignit...adigniter.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®

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

TeGGeR®

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.


--
TeGGeR®

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

TeGGeR®

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.


--
TeGGeR®

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

jim beam

TeGGeR® wrote:
> Kevin McMurtrie <mcmurtri@dslextreme.com> wrote in news:mcmurtri-
> 8690B7.21204230052005@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/ignit...adigniter.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.

>
>
>
>>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.
>
>
>

jim beam

TeGGeR® wrote:
> Kevin McMurtrie <mcmurtri@dslextreme.com> wrote in news:mcmurtri-
> 8690B7.21204230052005@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/ignit...adigniter.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.

>
>
>
>>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.
>
>
>

Jim Yanik

Kevin McMurtrie <mcmurtri@dslextreme.com> wrote in
news:mcmurtri-579156.17160130052005@corp-radius.supernews.com:

> In article <Xns966440B3E088tegger@207.14.113.17>,
> "TeGGeR®" <tegger@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/ignit.../howworks.html
>>
>> 2) Coil failure
>> http://www.tegger.com/hondafaq/start...s.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.
>

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

Jim Yanik

Kevin McMurtrie <mcmurtri@dslextreme.com> wrote in
news:mcmurtri-579156.17160130052005@corp-radius.supernews.com:

> In article <Xns966440B3E088tegger@207.14.113.17>,
> "TeGGeR®" <tegger@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/ignit.../howworks.html
>>
>> 2) Coil failure
>> http://www.tegger.com/hondafaq/start...s.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.
>

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®

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/