The IC inside the CDI

[Louis]

Maybe try this steps :
- ICP12 not plugged, put the switch to bootload mode (A from memory)
- Plug ICP12 on USB, the leds toogle green/red
- Upload the firmware, should be no errors
- Unplug the ICP12 from USB
- Put the switch to normal mode (B)
- Plug the ICP12on OEM board (4 wires)
- Power the loom with 12v
- Green led should toogle slowly

That is no different from what I'm doing.

Isn't it strange that the Oem circuit board without IC is holding a steady ignition point through the rpm range?
Thought i found something interesting.

So your experiment is mechanical angle is 36° on 3MA CDI

35 or 36 it was a bid between.

[tzr-v4]

The IC is only there to wait a delay after the pickup signal before firing the ignition.

So as the signal forms are similar 5V and active on falling edge to 0V, you could plug pickup to ignition.

For the ICP12, you can try to upload in the original firmware from piccircuit and use the smartDAQ windows application to see if ICP12 works.

Keep me posted.

[Louis]

The IC is only there to wait a delay after the pickup signal before firing the ignition

Ok, I thought holding it steady was the big problem.

Can we not use this?
To hold a steady 35 degrees you have to do some advance calculations to, what component on the OEM board is calculating this? (with rising rpm)

Is it not possible to measure this and see how much it is delaying the signal to hold it so steady as it is.
We can compute it back to hold a 19 degrees steady

Keep me posted.

Will do

[Toop]

 Olivier, do you want me to lend you my timing light (with shift) ?

[tzr-v4]

No calculation is needed to hold a 36° steady advance.

35° is the mechanical angle before the TDC when the lobe passes the pickup.
Direct connection is no delay => fire as soon as the pickup detects the lobe.

To make a 19° steady flat ignition, you have to wait 16° from 35° to get the 19°.
But the delay is linked to rotation speed in °/s so the faster your engine turns less time you need to wait to get the 16°.

I'll try to borrow a numerical signal generator to run some tests.

Bike will have to go back to running setup as a track day is booked next Monday at Pau Arnos 
http://www.circuit-pau-arnos.fr/page_accueil.php?language=en

[tzr-v4]

Olivier, do you want me to lend you my timing light (with shift) ?

Thanks TOOP but my car mechanic will lend me his facom one as soon as he has setup his 300 GAS-GAS 

[Louis]

No calculation is needed to hold a 36° steady advance.

35° is the mechanical angle before the TDC when the lobe passes the pickup.
Direct connection is no delay => fire as soon as the pickup detects the lobe.

To make a 19° steady flat ignition, you have to wait 16° from 35° to get the 19°.
But the delay is linked to rotation speed in °/s so the faster your engine turns less time you need to wait to get the 16°.

You are completely right

I was already lying in bed , where I figure it out I'm thinking way to difficult
(My mind was fixed on finding a steady point, and there you had it, wasn't thinking further)

36 degrees is a fixed position, like the old femsa ignitions (only one point)

Off to bed now (again), Good night

[tzr-v4]

will do the same... lecturing on mecatronics tomorrow 

[tzr-v4]

Will go to my car mechanic very soon as he has to fix my commuter car so I'll take the strobe timing light from him 

So IC thread will go on again 

[Louis]

So IC thread will go on again

Great

Have order a USB two channel oscilloscope to see if I can measure the same results as you.
Could be handy for future development, and knowledge for me to understand the CDI better.

I'll be interested in your results

[tzr-v4]

I'll have to setup some tests to be more efficient in developing.

I may need to have a bench like you Louis.

[Louis]

I'll have to setup some tests to be more efficient in developing.

If all goes well, my usb two channel oscilloscope is getting here next week.
I could provide you with some data at different revs.

Is it not possible to read out the old IC in order to see how they write it?
Perhaps they revile some secrets
The IC could be close to the : FUJITSU MB88P505H series.

I may need to have a bench like you Louis

If you feel like making something, here is the build off my ignition tester
(but think you need twice the power/speed of that engine to let it rev more)
http://www.tzr3ma.com/start-build.html

[Louis]

Well today came my USB two channel oscilloscope and I immediately put it in action

Instead of giving me answers, it gave me more questions

First thing was to measure the Oem IC, so soldered some wires to measure the IC working

-Pickup signal
-Ignition signal
-two mass

First od thing I discover is that the 3MA CDI is working without IC.
Without IC i measured 19degrees and going down to 17 degree when RPM is rising (same as with the iCP12 connected)

So first question is, way is it working without IC and where is the Circuit board getting his signal
is the pickup signal split into two signals
-IC signal
-Circuit board signal

Second od thing:
First impression is that it looks like the Pickup signal is changing in length when you turn the TPS sensor.

Here you have a snapshot with TPS in full throttle position (Green signal)
You see the short second pulse is now small



Here you have a snapshot with the TPS in closes position
And now the short pulse is long



Also it looks like the ignition point it self is placed in the middle of nowhere.
It is getting late now, will measure it further tomorrow.

Olivier, can you check one thing for me.
Does your bike start/run, without any IC or iCP12?

[jools]

Louis

have you traced out the circuit board of the CDI to produce an internal wiring diagram ?

This may answer some of your questions.

[Louis]

Hello Jools,

I'm trying to do that, but its not my field off expertise (so going slow)
Also the wax that is glued on the CDI, does not help me to find the routes the signal travels.

Still workibg on that.

What did I discover today:

It seems that the IC pickup signal is coming from the T2333 on pin4


The T2333 seems to be something like a Pulls conditioning device making a digital signal from analog signal
But it generate also different pulses (perhaps used on a other part of the circuit board)

ALso noticed that the Pickup is having a ''noise'' when ignition rpm rises
Clean signal low rpm:

Noise at the fist part:


Here we have some snapshots with no IC (nothing controls the CDI)
When RPM is rising you see slowly that the two points are shifting:
35Hz

68HZ

118HZ

455Hz


Now I'm thinking something else.

Would it be possible that the 19degrees is hardwired in the CDI unit (du to different components like the T2333)

That the IC is only calculating different degrees from that point (19) when it hits a certain RPM
The timing light is confirming that theory na bid, as when the engine revs very low rpm's you see it shifting to (with oem ic)
When going from 350rpm to a 800rpm you se the degrees moving to, until it hits the 19degrees than it is stable
(it feels like the IC is taking over)

But it will probably be me thinking to difficult