Ignition updates to the Unofficial FAQ

Kevin McMurtrie > wrote in
:

> In article >,
> "TeGGeR®" > 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.






--
TeGGeR®

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

Kevin McMurtrie wrote:
> In article >,
> "TeGGeR®" > wrote:
>
>
>>Jim Yanik .> wrote in
:
>>
>>
>>>"TeGGeR®" > wrote in
:
>>>
>>>
>>>>Randolph > wrote in
:
>>>>
>>>>
>>>>>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/educat...nction/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/ignit...ion/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.
>
>
> Most materials have an electron flow, which goes from negative to
> positive. I've heard that some materials can have a proton flow.

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.

> 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.)
>
>
>
>>http://www.tegger.com/hondafaq/ignit...ion/index.html
>>http://www.tegger.com/hondafaq/ignit...adigniter.html
>>On these two pages, is the current flow through the transistors correctly
>>depicted? Nobody has answered that question yet.

"TeGGeR®" > wrote in
:

> Jim Yanik .> wrote in
> :
>
>
>>>
>>
>> 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/educat...tion/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/educat...tion/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/educat...tion/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.

--
Jim Yanik
jyanik
at
kua.net

Jim Yanik .> wrote in
:


>
> 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?

--
TeGGeR®

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

"TeGGeR®" > wrote in
:

> Jim Yanik .> wrote in
> :
>
>
>>
>> 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?
>

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.)

--
Jim Yanik
jyanik
at
kua.net

"TeGGeR®" > wrote in message
...
> Jim Yanik .> wrote in
> :
>
>
>>
>> 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?
>
> --
> TeGGeR®
>
> The Unofficial Honda/Acura FAQ
> www.tegger.com/hondafaq/

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 .> wrote in
:


>
> 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.

--
TeGGeR®

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

"TeGGeR®" > wrote in
:

> Jim Yanik .> wrote in
> :
>
>
>>
>> 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.
>

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.

--
Jim Yanik
jyanik
at
kua.net

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 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.

--
TeGGeR®

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

----- 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