RE: New CDI - opensource project JMJ and Bigboat
 

Below 1800rpm, the ignitionpoint is 15 degrees BTDC or 25 degrees count back from 40 degrees.
Into the code you can see this in line 19, delay <1800 RPM in degrees
This can't be change, the timers needs some time to calculate the ignitiontime.
The pic will do this between 40 degrees BTDC and TDC, thats why I need 15 degrees.
The flashlight isn't acurate under 1800 RPM, the flash foling around a bit.

RE: New CDI - opensource project JMJ and Bigboat
 

Rob
why dont you move the Hall to 80 degree BTDC then it has more time, that way the lower start timing can
be reduced even more, eg 10 degrees +

brett

RE: New CDI - opensource project JMJ and Bigboat
 

Rob, I have very small capacitors here..large values with my parts aren't a problem. I don't use the regulator because I use only a 4.8 volt battery. Tested the changed PCB today.. works great! Thanks for adding the new features.. wish I could use that program to design my own boards..no time to learn, but plenty of time to make boards!

RE: New CDI - opensource project JMJ and Bigboat
 

The Layo1 program I use is Dutch and DOS, but you can download a english version also.
The DOS version is a easy to use version, I can't work with the window version.
I use the window version only to convert from DOS to windows.

EDIT: timerboard (CDITCITM) and TCI-powerboard (TCIPWR1) has be changed.
I place the TIP162 and the regulator at the backside of the PCB's.
I need the space this components take for other components.

RE: New CDI - opensource project JMJ and Bigboat
 

How I make my pcb's http://www.electronics.gompy.net/pcb/

RE: New CDI - opensource project JMJ and Bigboat
 

Rob, I got the newest timer board functioning with my CDI board.. I replaced R4 with a jumper and it worked. now to figure out what to place in the other positions..
I know you had instructions on the bottom of the schematic, I tried that..shorted the pulse signal to ground and didn't trigger mine. I'll experiment...parts are cheap!

I took apart 4 computers and stole parts from them to make this last board..but it works! The new board is really small..I love it! Fits inside my fuel tank compartment on my 60 size Stinger. I run a K&B .61 on spark ignition on that one using regular weedeater fuel..worked great before, now I can take the throttle coupled spark advance linkage off and use the new timerboard! WoW! Things have come a long way since you and JMJ first started this project!

We still need to rewrite the C-code though..make it easier to change the data and timing..wish I knew that part of it..
Maybe someone can help us do that now that all of us have boards that finally work.

I got my other PIC chips today..ready to program a new timing curve.

Pics of the newest smaller timerboard, and my latest conversion ready to mount and test run...
it's from a Cox chainsaw..1.4 cubic inch.

John

RE: New CDI - opensource project JMJ and Bigboat
 

Nice PCB's you have make !
I put some new drawings on the website of the timerboard and hope everyone can understand the meaning of the resistors at the output.
This timerboard will be OK for the next coupple of years and can work wtih all codes.
It's not necessary to have a program in C-code, it can also be (pic)basic, asm or other language.

The engine looks new to me.
In the Netherlands we can buy a chainsaw or weedeather, but the price is very high (between 200 and 400 euro)
If I take a look to some sites in the USA, I get 5 engines for this price !

I buy meself a few spy carkey cams on ebay to make flyght movies with my aviators......I don't have plains anymore, it cost me a fortune [:o]
All the places where we can fly are much to small and there all everywhere houses and roads.

RE: New CDI - opensource project JMJ and Bigboat
 

Good job john. You got way too much time on your hands.:). I like that engine.Are the cox chainsaws still around?

RE: New CDI - opensource project JMJ and Bigboat
 

Yes John very nice work......could be your new Job haha

here is a power board i was testing tonight with car coil and 11 volts,

fitted the wrong cap which made to self run

http://yfrog.us/jpdscn2462z

brett








edit:spelling, sorry its late

RE: New CDI - opensource project JMJ and Bigboat
 

Never mind John about the cox. I see that they are antiques.

Nice setup Brett.

John wrote:

I agree. the spark table need to be written to eeprom and then to change the curve instead of compiling the whole source code, update the eeprom with new values. Using ISCP update the info with the pic still in the timing board.

RE: New CDI - opensource project JMJ and Bigboat
 

Looking at the new timing board. I see a use for one of the outputs. It can be used for a tach output.

RE: New CDI - opensource project JMJ and Bigboat
 

You can connect a tacho also on the flashlight output.

RE: New CDI - opensource project JMJ and Bigboat
 

Brett, wat are you doing ??????????
You connect a car(spark)coil to a CDIHVbaord ???????
The scr can't handle this and also the C can't deliver the power you need for this coil.
And if any goes wrong, you blowup the carcoil with the Voltage (300V) of the HV-board.

Left the CDI-coil and the blue one is a carsparkcoil

RE: New CDI - opensource project JMJ and Bigboat
 

Hi everyone..
That Cox engine was one of 10 I bought at a yard sale for about $1 each!..over 5 years ago. It was popular maybe 10 years ago but none are around anymore.. It was used as an airplane engine under the name Roper 1.4 ....many years ago, and was run on glo fuel only. This is one of 3 that I had converted for use on a Nosen 104 inch Citabria with ignition conversion.
Since I am currently out of work, I spend about 20 hours a day on making boards and testing. I think I'll have to concentrate more on the software end of this project soon, since everyone has problems with that part.
Maybe with more drawings, details of the circuit operation and a an all inclusive HOW-TO do this, we can make some more progress!
The initial posts left alot to be desired, but it's all taking shape Charlie!
When we all work together, GREAT things can happen! I know others are reading these posts, so let's hear some input on the work done here. Rob, you are doing a great job with new things for all of us. Keep the good things coming!

John

RE: New CDI - opensource project JMJ and Bigboat
 

If there is a good HOWTO, the software can't be a problem.
Draw the curve you like, copy the code from the Exelsheet to MicroC, press build and shoot the hex-file into the pic.
I think how to use this programs will be a problem, also wat is a CDI and how do I build the CDI to my engine is a problem.
With other words.....we need a howto !:)

RE: New CDI - opensource project JMJ and Bigboat
 

Rob
it is just a test board as my CDi coil was on my bike, and i had a bobbin already with only 375 turns from
another project

this is my normal CDI coil

http://shop.scootling.co.nz/index.ph...;productId=475


funny enough the scr was the only thing that didnt get warm......

have you/anyone tried different size cap's ???? is the 470nF best for spark or best for least current draw


brett

RE: New CDI - opensource project JMJ and Bigboat
 

I try everything.....big / small, you name it, I test it [8D]
Wat Voltage is your HV-coil on the board making and wat power can he generate.
The loadtime is important, if the cap isn't fully loaded, the sparkcoil can't make the right spark.
Somewhere in this topic, or the other, I explain wat type of cap you need to make a right spark.
If your engine not run like hell, you can use a smaller cap.

RE: New CDI - opensource project JMJ and Bigboat
 

I do not trust my Digital multimeter, it says 932 Volts DC, i think there is interference from the circuit

do you remember if the posts about the Cap's were in this thread ?

I rang up a Bosch agent in NZ

GT40RT 1.6 Ohms
GT40T 2.97 Ohms
MEC717 .45 Ohms
HE715 .41 Ohms
MEC723 .45 Ohms

Max current draw 5-6 Amps

brett

RE: New CDI - opensource project JMJ and Bigboat
 

<>
We gone do some calculation to understand the powerboard,

To get a big/strong spark, we need Joules.....a lott of Joules, mega Joules.
For a good spark and a high rpm we need about 90 mJ. (45 mJ for ~8000 rpm)
This Joules we get from the capacitor and the high voltage coil on the powerboard.
If we have 300 Volt from the coil and the capacitor is 1 uf, we have (0,5*C*(U*U)) = (0,5*1*(300*300)) = 45 mJ
With this calculation you can see we don't have enough Joules.
Wat can we do about this.....
Increas the capacitor, but you get a longer load time....not good !
Increas the voltage, easy to do......more windings.
If we have 600 Volt from the coil, we get (0,5*1*(600*600)) = 180 mJ, we need only 90 mJ !
Now we can decreas the capacitor to 0.5 mF, this will also decreas the laodtime from the capacitor to 1/2 of the normal loadtime.
If the laodtime from the capacitor will be shorter, the rpm will be increas.
We need also some current with this voltage.
A easy way to do this is to wind prim two windings (to gether) on the coil (2x 20 windings of 0.5mm).
The sec-winding must be increas to ~1200 of 0.1mm to get ~600 Volt.
BTW, don't forget to make the resistor of the ocsilator smaller ~1/2 of the normal value for a higher rpm.
</>

RE: New CDI - opensource project JMJ and Bigboat
 

**** happens, I blow my sparkcoil and the hallsensor.
The ground wire wasn't connect to the ground of the batterie.
The spark goes straight over the pcb.....I glad no more components are distroyed.

RE: New CDI - opensource project JMJ and Bigboat
 

Thanks for the explanation Rob,


today i got the correct parts for my power board....BUT it is still self running,

i have the 1 k resistor on the gate of the SCR to earth and that is all

i shouldnt need any other compontents ???

my car coil measure's .7 Ohms

brett

RE: New CDI - opensource project JMJ and Bigboat
 

It lookslike the scr is firing by his self, maybe a spike firing him up.

Remove C1-0,1uF (on the new drawings) and put a resistor (10R) on this place.
Chnage the R1 (1K) resistor to 470R and put a capacitor (0,01nF) over this resistor.
If this isn't help, remove C1 and replace it for a 1N4007.

It's also possible the flyback Voltage firing the scr.
Take a resistor (180R) and a capacitor (0,01uF/630Vac) in serial.
Mount the two componets between ground and the anode of the scr.

RE: New CDI - opensource project JMJ and Bigboat
 

@Brett, you can't measure a coil with a normal digitalmeter.
If the coil is made from wire 0.1mm^2 or 2mm^2, the resistant will be the same, but not the current the coil can handle.
Copper have a resistant of 0.0175R / meter, so there is 40meters of wire on your coil.....thats all we know now.

RE: New CDI - opensource project JMJ and Bigboat
 

Rob,
i do not have C1 in the circuit,

just gate tired ti groung with 1 k resister, ( i tryed 470 with .01nf across it with no change,

i didnt have a .01 uF but i had .022 and the 180R

this made no change also

my bobbin is very loud, what Hz does it work at ?

it wouldnt be the test board i am using (white bread board) with the contacts close together

brett

RE: New CDI - opensource project JMJ and Bigboat
 

Only the scr can firing the coil, I think the rsc is going to the huntingfeelds.
Now the coil is loaded with the same frequentie like the HV will do ~4kHz.