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Old 07-03-2014, 11:57 AM   #61
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Quote:
Originally Posted by DaveC View Post
Personally, I think it's an abomination to drive anything off-board directly from CPU pins. (I am an EE and design embedded systems for a living.)
The CPU does not directly drive the spark outputs, please see my previous post.
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Old 07-03-2014, 11:57 AM   #62
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EDIT:Ben just posted some SERIOUS drive capability!
Is that full sink/souce? Anyway, if the mspnp2 v1.3 has these kind of stats then the problem is somewhere else.
If someone is running into these issues using the old school spark driver circuits then read on.

Dave brings up some good points.
I'm going to reiterate one of Dave's comments:
Even with a 100ohm pull-up you'll be seeing a 1v drop on a 10mA load.

That's why I recommended the full swing digital buffer. +/- 50mA current drive should lick this. But Bryan has to deal with a 20 pin dip package...
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Old 07-03-2014, 12:02 PM   #63
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Originally Posted by FAB View Post
Thank you -

Information I do have:
  1. 3-4 guys running MS have had trouble running them on wasted spark.
  2. One of them happened to scope the signal while the car was running and saw a max of 4.2v and the components used in the ignition module state a minimal of 5v is required.
  3. Some MS customers don't have the issue at all. (maybe they are running sequential) Some customers with piggy back systems or timing cards have the identical issue.
  4. I've also discovered that increasing the signal voltage solved the problem and that if increased too much it will destroy the ignition module in a short period of time.
  5. It's not a matter of the components ability to produce a strong spark. My personal car ran the exact same kit I ship to customers at very high boost levels for the past 4-5 months. I'm using an AEM EMS4, sequential.
So you have an ignition module that works with some MegaSquirts, but not others. It works with some piggy backs, but not others. Yet you are blaming the MegaSquirt product. It seems more likely that the "threshold" problem is inherent to your ignition module. I think you need to at minimum provide some specs for your ignition module, specifically relating to its signal input requirements.

I also see references to a CDI module, but the module I see in photos is a standard VAG inductive module.

I think you need to provide better specs before pointing fingers.
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Old 07-03-2014, 12:20 PM   #64
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Quote:
Originally Posted by leboeuf View Post
EDIT:Ben just posted some SERIOUS drive capability!
Is that full sink/souce? Anyway, if the mspnp2 v1.3 has these kind of stats then the problem is somewhere else.
Source
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Old 07-03-2014, 12:21 PM   #65
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Quote:
Originally Posted by Ben View Post
So you have an ignition module that works with some MegaSquirts, but not others. It works with some piggy backs, but not others. Yet you are blaming the MegaSquirt product. It seems more likely that the "threshold" problem is inherent to your ignition module. I think you need to at minimum provide some specs for your ignition module, specifically relating to its signal input requirements.

I also see references to a CDI module, but the module I see in photos is a standard VAG inductive module.

I think you need to provide better specs before pointing fingers.
Let's be clear, I'm not pointing any fingers in "blame". Everything I've said to this point has been simply from observation, it won't work with some MS units when configured in wasted spark. The "threshold" is inherent to a module that MegaSquirt already has documentation on.

I'm willing to produce a harness (and provide it free of cost) to solve the problem so my customers do not have to modify their components to properly drive our kit.

You're correct, it's not a CDI module it's a standard inductive driver - THIS module.
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Old 07-03-2014, 12:55 PM   #66
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Quote:
Originally Posted by FAB View Post
Let's be clear, I'm not pointing any fingers in "blame". Everything I've said to this point has been simply from observation, it won't work with some MS units when configured in wasted spark. The "threshold" is inherent to a module that MegaSquirt already has documentation on.

I'm willing to produce a harness (and provide it free of cost) to solve the problem so my customers do not have to modify their components to properly drive our kit.

You're correct, it's not a CDI module it's a standard inductive driver - THIS module.
That's not exactly how some of your statements read, I've been following for a while but was attempting to keep some distance.

Are you using GENUINE Bosch 211 modules or Chinese knock offs? Genuine Bosch 211 modules are known to trigger in wasted spark off fairly low current outputs.
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Old 07-03-2014, 01:33 PM   #67
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Thinking that might have been a simple fix, I've tried the Bosch unit, and 3 other modules from various manufacturers. Unfortunately with identical results.
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Old 07-03-2014, 03:03 PM   #68
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To be exact it's 99-00 MS2PNP on MS2/E release 3.2.5
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Old 07-03-2014, 04:39 PM   #69
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Originally Posted by FAB View Post
Thinking that might have been a simple fix, I've tried the Bosch unit, and 3 other modules from various manufacturers. Unfortunately with identical results.
What MegaSquirt variant do you have? What is your battery voltage? What is your dwell? Datalog and msq would be helpful.

The 211 module is simple to drive. They are extremely popular, especially in Europe where they are dirt cheap and common. They are more expensive in the US. There is something else here.
I would avoid Chinese knock offs.
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Old 07-03-2014, 04:53 PM   #70
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Given the lack of answer it's pretty much confirmed that they're using the cheap knockoffs.
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Old 07-03-2014, 05:15 PM   #71
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Quote:
Originally Posted by Ben View Post
What MegaSquirt variant do you have? What is your battery voltage? What is your dwell? Datalog and msq would be helpful.

The 211 module is simple to drive. They are extremely popular, especially in Europe where they are dirt cheap and common. They are more expensive in the US. There is something else here.
I would avoid Chinese knock offs.
I don't have MS but the system we're speaking of is owned by Impuls and he has a 99-00 MS2PNP on MS2/E release 3.2.5


Quote:
Originally Posted by albumleaf View Post
Given the lack of answer it's pretty much confirmed that they're using the cheap knockoffs.
Why, thank you for your kindness. They aren't Bosch but they certainly aren't cheap. The Bosch module alone would add nearly $100 to the cost of our system and offers no worthwhile benefits that justify the costs.

We use a module distributed through SMP (Standard Motor Products). Local, warranty, reliable. We also went this route because in the US the same module can be purchased through any Advance Auto Parts stores.
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Old 07-03-2014, 06:17 PM   #72
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Quote:
Originally Posted by Impuls View Post
To be exact it's 99-00 MS2PNP on MS2/E release 3.2.5
Mine is a 94 DIYPNP 1.5b with the microsquirt board built by Brain himself.

Same issue.

I could possibly datalog mine as well. In fact, i may have a datalog of it somewhere, i can't remember if we got one or not.
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Old 07-03-2014, 06:21 PM   #73
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Quote:
Originally Posted by Erat View Post
Mine is a 94 DIYPNP 1.5b with the microsquirt board built by Brain himself.

Same issue.

I could possibly datalog mine as well. In fact, i may have a datalog of it somewhere, i can't remember if we got one or not.
Dillon (Erat) owns the car we tested a handful of different modules on without changing results.
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Old 07-03-2014, 06:27 PM   #74
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As well as a bunch of different dwell settings. We took the dewll up to the point of smoking an ignition module.
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Old 07-03-2014, 07:22 PM   #75
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"I need to know how much current the FAB9 ignition module requires.
Thanks,

Matt Cramer
DIYAutoTune.com"

Common guise..
This thread wasn't made to bash anyone.
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Old 07-03-2014, 07:35 PM   #76
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Thanks for sharing the product number of the ignition module.

The Bosch datasheet clearly states it needs 10mA minimum for proper operation.

Example schematic of Bosch:


Now the module is nothing more than 4 bipolar transistors in a package, so no rocket science at all. One thing we shall not forget: bipolar transistors turn on and off due to _current_: so voltage is not that important.. You will need a certain current to make these things work OK. Too much resistance and you will run into trouble.

Looking at the example schematic they use a resistance of around 200 ohms from 5V to turn the transistor on: yielding a current of around 20mA (assuming 1.0V Ube during saturation) through the pin of the module. They use a 33 ohm resistor to turn the thing off: I think this is important as you want to turn it off quickly to generate a nice accurate spark.

Please note if you connect two channels in parallel to run wasted spark the current requirements double so you would need half the resistance to make it work OK.

I am wondering when you drive the thing directly of the pin of the MCU if the MCU is actually capable of driving 40mA. Does somebody know if you could expect 40mA ?

If you want to boost the logic signal you can clone the Bosch schematic and use any run-off-the-mill transistor with similar specs as the BCX 58.
If you want to make a bit better you can use something like a Microchip TC4469/TC4467 (or similar) with a 150 ohm (or a bit less) resistor in series with its output. You then have the ability to quickly turn the module on and off. This will somewhat limit the heat generated inside the module compared to the Bosch' example schematic.
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Old 07-03-2014, 07:46 PM   #77
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Quote:
Originally Posted by DaWaN View Post
Microchip TC4469/TC4467 (or similar) with a 150 ohm (or a bit less) resistor in series with its output.
Ahh nice driver chip! I was looking for something like that this morning to post into this thread.
Fab, take note, if you can find this IC use it instead of that other one I linked.

Do you really need the 150ohm series current limiter? If your schematic is correct, it looks like the 10kohm in-line within the igniter should handle the current control?
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Old 07-03-2014, 07:53 PM   #78
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Quote:
Originally Posted by leboeuf View Post
Ahh nice driver chip! I was looking for something like that this morning to post into this thread.
Fab, take note, if you can find this IC use it instead of that other one I linked.

Do you really need the 150ohm series current limiter? It looks like the 10kohm in-line within the igniter should handle the current control?
Yes you really need the 150 ohm series resistor!
The schematic posted above is an example schematic for use inside the ECU to drive the ignition module, so the 10k resistor is used as a base resistor between the MCU of the ECU and the driver transistor.

The series resistance the module 'sees' during operation is 183 ohms when dwelling and 33 ohms when it needs to ignite. This is important as bipolar transistors are current driven: so without resistor you will most likely damage the transistor because of a high base current. You will only need 10mA to put the thing into saturation, anything more does not bring any benefits to your spark.
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Old 07-03-2014, 08:09 PM   #79
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Hmm interesting.
Do you have the schematic of the ignition module?
It seems unlikely that they would design it without any current limiting resistance on the input pn junction. But I've certainly been wrong before!
I could see the necessity of the series resistance if you were using a raw ignition component like the bip373, but I thought the COP ignitor was built to handle raw (high current potential) digital voltages?
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Old 07-03-2014, 08:14 PM   #80
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Quote:
Originally Posted by FAB View Post
You're correct, it's not a CDI module it's a standard inductive driver - THIS module.
Waitaminit. I thought your kit was CDI? If they're inductive and use Bosch or Boschlike modules, why does dwell not matter?

That Bosch ignition module requires a pretty heft amount of current, 10 mA.
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