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coil ignitor noise 
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I am a big KISS fan, but as I say, as simple as possible, but no simpler.
It looks like just using a resistor like they did with a single coil is too simple
for these small COP coils. At 2,000 rpm I believe its about 15ms between firings,
so that is quite a waste of energy. oh well, so much for the Duraspark modules.
They are rather large units for what amounts to a single transistor.
I did get a Bosch ignitor from a 1.8 VW, thought I'd use it in another project that needed 3 cyl control,
but looks like I'll just use it for the tractor.


Tue Nov 15, 2011 4:19 pm
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There is nothing wrong with your duraspark module (I think), It's how you're using it.

The resistor on single coil setups on cars is a balast resistor which is switched out of the circuit while cranking such that the low voltages present can properly charge it. It's still dwelled for X ms just like a modern system, even if it's points driven.

I think you need to study ignition systems a bit more before proceeding.

Fred.

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Tue Nov 15, 2011 10:01 pm
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I'm curious why did you choose the MSP430?


Last edited by Fred on Wed Nov 16, 2011 12:41 pm, edited 1 time in total.

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Wed Nov 16, 2011 2:23 am
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jharvey wrote:
I'm curious why did you choose the MSP430?


Fred, have you worked on 1970's cars? Do you know what a Duraspark is? It replaced points in 74-79 ford cars.

I'm using the MSP430 because when it came out years ago it was very low power and very inexpensive.
I used them for a number of things, but mostly I created an R/C race controller with it using 2.4Ghz,
no more conflicts using crystals, which was always a huge hassle when racing.
It was tiny and lightweight in the car, and in the handheld controller, it could run forever on a 9v, unlike the old technology which burned through a bunch of heavy AAA batteries. I have maybe 200 of them left from the business.
I also built battery chargers with them, still have lots of parts left over from those too.
So I'm using it mostly because I have them and already have experience with them.
I actually plan to start using the PIC processors in future products so I can use the CAN bus.


Last edited by Fred on Wed Nov 16, 2011 12:42 pm, edited 1 time in total.

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Wed Nov 16, 2011 3:36 am
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Jared, don't do that again. Discussing moderator actions on the forum is strictly prohibited, and you knew that.

nimblemotors wrote:
Fred, have you worked on 1970's cars?

Nimbie, I've worked on cars from the 50's, 60's, 70's, 80's, 90's, and 00's! = Yes!!!

Quote:
Do you know what a Duraspark is?

Yes!!!

Quote:
It replaced points in 74-79 ford cars.

You're not using the part that replaced the points as far as I can tell - that is the job of your MSP430. The part you're using is a giant ignitor.

If you look at any diagram of the duraspark system, you will see that the resistor is indeed used as I described. In fact, it was used that way on virtually every points and points equivalent system (such as duraspark) since that error. Only more advanced systems (80's up) with computer controlled dwell did away with it as they could just dwell longer instead for low voltage and appropriately short for high voltage. It sounds as though you're doing neither of those things and trying to rely on the module to do your dwell for you.

You're welcome to ignore my advice, though. :-)

Fred.

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Wed Nov 16, 2011 1:04 pm
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Jared, you may repost if you observe the rules. Your last post was removed as it breached them again. Next time I'll take further action.

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Wed Nov 16, 2011 10:10 pm
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Freddie, WTF are you saying? And why do you feel the need to insult me?
There is no other way of using the Duraspark module than how I'm using it,
It can't be used to control dwell, it is NOT like an modern ignitor, and it doesn't control dwell itself like I thought it might,
by sensing the RPM, it just charges the coil right back after firing it.


Last edited by Fred on Thu Nov 17, 2011 9:59 am, edited 1 time in total.

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Thu Nov 17, 2011 3:55 am
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nimblemotors wrote:
Freddie, WTF are you saying?

Only this:

nimblemotors wrote:
It can't be used to control dwell, it is NOT like an modern ignitor, and it doesn't control dwell itself like I thought it might,
by sensing the RPM, it just charges the coil right back after firing it.

Exactly. It wasn't clear that you'd understood that yet. BTW, most modern ones don't do that either. It's usually left to the ECU to control on modern stuff too. Some oddball ones did do that, however duraspark was not one of them. You're miles better off without that anyway.

Quote:
There is no other way of using the Duraspark module than how I'm using it,

Wait, what? This _seems_ to contradict the above. How ARE you using it *exactly*? If you're using it with a resistor then there certainly are other ways. If your code now does proper dwell control, then you're right! One thing is for certain, you're not being at all clear about what you're doing and not doing.

Quote:
And why do you feel the need to insult me?

I definitely don't feel the need to do that. I didn't think I had done that, most certainly not on purpose. And when I checked just now I failed to find anything insulting in my post. I answered your 70's question, perhaps in a manner that you didn't expect, but that's about it. You could say you were being insulting asking those questions, it certainly seemed like it, however I didn't take it personally. If there was an element of cheekiness in my post, nor should you take it personally.

Fred.

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Thu Nov 17, 2011 10:06 am
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http://youtu.be/imQkWVtHjRs

The final hardware running the tractor, maybe the 15 people who say the original want to see it running the tractor. :)
One issue I ran into was after some testing cranking it, the battery was run down
such that the crank RPM's were so low, that the timing between tooth were highly variable because of compression, etc, so it would not recognize the missing tooth. Once I hooked up the battery charger and got it to crank smoothly,
it started up and ran. and I might add it runs smooth now, unlike before with the bad distributor such it ran on 1.5 cylinders.


Tue Nov 22, 2011 2:32 am
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Cool! Congratulations! :-)

BTW, you will find that if you rotate your timing wheel on the engine to a different place the software will have a better chance of handling such low voltage conditions. If it's in a bad place it affects the "contrast", otherwise it doesn't.

Fred.

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Tue Nov 22, 2011 3:11 am
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