It sparks by CDI

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It sparks by CDI

Post by beat » Sat Jan 05, 2008 10:26 pm

hi al,

<127 <017 <018 <004 <059 <115
beat

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Post by steve m » Sun Jan 06, 2008 2:44 am

hi beat,
more easy words to understand :smile:
is this the project you started about a year ago, to make the points last forever? did you fit to the bike?
or, are you just saying hi to all? :???:

steve

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Post by beat » Sun Jan 06, 2008 6:47 pm

hi steve m
no, this is not the project I started one year ago. it was a Transystore - Coil - Ignition, it is nicely finished. so it is a INDUCTIVE system and is running well in my bike now. The timing of the spark is stil done by the points, and yes, they will last fore ever.

the one I starting now, it is a CAPACITIVE system. The timing of this spark will be done agayn by points, and also in this case they will last for ever.
the next two pictures showing a diagram of each system.
at first the INDUCTIVE one, as to se, it contains only a few electronic elements. ruffly say a half a docent.
Image
I have not built exactly this as to see on the pic, fore the real details look at IT sparks topic please.

If we have a look on to a diagram of a CAPACITIVE system, it shows fore example this
Image
ore a other one would be this one
Image
it loocks a bit different, contains abouth 20 to 30 electronic elements and there are different layouth posible to reach the more ore less bether result.
now I must say, I am not a electronic expert at al, I have nearly nothing to do with this stuff on my job, so it is just a hobby of mine whilst wintertime.
- sorry, have to interrupt here, have to go to work immidiatly
beat

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Post by minetymenace » Mon Jan 07, 2008 12:28 am

How it works (well the first one anyway)

T1, T2, Tr1 R2, C5, C1 and G form an oscillator, step-up transformer and bridge rectifier constitute a DC-DC converter that creates a large DC voltage to charge C3.

When the points (S2) open, thyristor Th1 fires and the energy in the capacitor C3 discharges as current through the coil producing a spark.

Its late now and I need to go to bed, but the other one can't work as the circuit is on its side (unless you lay the bike down) and all the electrons will fall out...

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Post by steve m » Mon Jan 07, 2008 12:55 pm

ah, finally,it make sense- bike on side , lecky falls out ;-) :lol:
now your talkin my level

steve
Last edited by steve m on Sat Oct 24, 2009 12:14 pm, edited 1 time in total.

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Re: It sparks by CDI

Post by beat » Sat Oct 24, 2009 11:17 am

hi Minety,
can you have a look in to this one please ?
it seams to have some interesting components...
beat <127

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Re: It sparks by CDI

Post by beat » Sat Oct 24, 2009 11:19 am

sorry,
http://www.molla.org/DIY-CDI/#Deutsch
beat , houping it works...

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Re: It sparks by CDI

Post by Mark Cook » Sat Oct 24, 2009 11:46 am

Yes some interesing things have turned up in recent months Beat, the next trick is to figure out long burn CDI. A friends SEM CDI has started to missbehaive, so Sunday I will fit it to my test rig. Would be nice if Gerry popped over once it's running to help set up the silly scope so we can make sense of it's output. I have trouble locking the timebase to the wave form. The other nasty is trying to avoid feeding HT to the scope.

If all goes well I might pop you some experimental goodies in the post for you to play with. As for the pot cores and formers I've found a US/chinese company that seems to do loads of stuff.

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Re: It sparks by CDI

Post by minetymenace » Sat Oct 24, 2009 12:53 pm

couldn't open the english details beat!! Sout be able to pop over Sundat Mark, what time?
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Re: It sparks by CDI

Post by beat » Sat Oct 24, 2009 8:35 pm

english is just above the deutsch one, just scrolling upwards it is ?
mark, do the US/ chinese have a catalog in internet ?

as my glued transformator gets the windings this afternoon, it looks nice so far...
BSA1055.jpg
preparing al the necessary stuff
BSA1056.jpg
winding 42 tourns with 0.8mm wire by free hand
BSA1057.jpg
primary bobine
BSA1058.jpg
preparing for 1000 secondary windings
BSA1059.jpg
the winding-machine in action
BSA1060.jpg
over 1000 windings with 0.30mm wire for secondary bobine
BSA1061.jpg
and al in the glued ferrite
so, soon it has to go on to the switching mode for the oszilator.
I have decidet to try a own way to do it, not to fallow one of this old electronic layout as above.
will "outing" the details soon,
beat, ( the hands are again faster then the brain <941)

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Re: It sparks by CDI

Post by Mark Cook » Sat Oct 24, 2009 8:44 pm

I guess I'll have it up and running around 3pm Gerry, need to tidy up first so I can find the electronics bench :laugh

This should sort you out Beat http://www.cosmocorp.com/en/bcat-main.cfm (others might not agree :lol: )

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Re: It sparks by CDI

Post by minetymenace » Sat Oct 24, 2009 11:33 pm

Had a bit of an auto-arbour incident <910 so will be off air for about a week, sorry Mark can’t make it Sunday. (All will become obvious when I get some photos for the Tale of Woe section).

Paid a fascinating visit to a coil winder the other day, he just does magnetos, but had a good chinwag anyway. Beat, love the way you say “over 1000 turns”, more the merrier on the secondary, pack them in till its full. For reliability dip coil in shellac (or varnish thin enough to get into the windings, maybe cook it for a while) to stop the coils moving relative to each other as all that energy flies about. Do you have a Megger? To preserve the insulation on your coil, never leave the secondary output open circuit when you test, always have a small, but representative spark gap (too big a gap, and the discharge will occur in your transformer.

Just noticed you have brought both ends of the secondary out at the same via, best to keep them well apart if possible, say opposite sides of the core..
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Re: It sparks by CDI

Post by beat » Sun Oct 25, 2009 11:31 am

hi minety,
yeas, the glueing of the coil is in my plan as soon I have tested it. thanks for the advice for the not open secondary coil wheil testing, I was not thinking about this....
a megger I can barrow out for testing, I do not have a own one. I will se for it.
about the two ends of the secondary coil: good advice to separate them, I missed this one.. :oops:
as for the tousend windings : I realy have more ore less counted to 1000, then I have just filled the thing. :cool:

beat
so, next step will be : using a IC as a oscilator where on I can adjust the frequency of the transystor to interrupt the 12 Volt for the primary coil.
( have to put my nose deep in to the boxes of "spare parts" my son and myself have collected ), and of cause <929

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Re: It sparks by CDI

Post by beat » Sun Oct 25, 2009 9:18 pm

hi minety,
minetymenace wrote:To preserve the insulation on your coil, never leave the secondary output open circuit when you test, always have a small, but representative spark gap (too big a gap, and the discharge will occur in your transformer.
how can I anderstand this one ?
is at 300 volts already a danger to breack the bobine ?
should I conect for the testing already the bridge and the 1uF capacitor to avoid damidge ?
beat <004

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Re: It sparks by CDI

Post by beat » Sun Oct 25, 2009 9:26 pm

I have forgotten to ask, : have you heard about this programmable IC " AT Tyni 13" ?
smal in size and sloopes are to set in time and waiting time as well. It offers the oportunity to work with this TAN- Time of the primary coil and use the Transistore in a save but full range and time...
beat :?: :?:

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Re: It sparks by CDI

Post by minetymenace » Sun Oct 25, 2009 9:46 pm

Yes beat, I've heard about it , the characteristics (as you explain them) have stirred a new wave of interest that is going to make me dig out old papers and download spec sheets just because it sounds so wonderfully fascinating :shock:
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Re: It sparks by CDI

Post by Mark Cook » Sun Oct 25, 2009 10:22 pm

I think what gerry was saying is to have a very small spark gap on the seconary during testing if it is not conected. If you run it open circuit it could brake down the insulation on the secondary.

Nice to see your still live for the moment Gerry :smile:
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Re: It sparks by CDI

Post by beat » Tue Oct 27, 2009 7:09 pm

hi mark,
how much is " very smal " ?? 0.2 mm , is it ok. ?

abouth the ruffly layout for producing a 300 volts DC out of 12 of them, I try it like this.
BSA1064.jpg
first ( not realy ) try for the 1:25transm.
I will also use a IC Bug to form the "Zerhacker" , waver ore oscilator ore what it is in english ?
as "Bugs" need the right feed, it has a "Festspannungsregler 5Volt" ( in english ?) in front of it.
Bug = AT Tiny 13-20PU
Feed = L7805ACV
the resistores are not decidet finaly yet, I need a other go on a next paper....
Minety, ore other readers, if you se faults in this droing, please let me know...
beat <965

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Re: It sparks by CDI

Post by beat » Thu Oct 29, 2009 9:55 pm

hi al,
stil fiddling on this CDI thing... to get something cut for my B50.
so, for the interested ones....

as there are good sites and bad ones on everiting it existes, most of the CDI systems suffers on a very short spark duration of only 0.2 mill.sec. for one spark.
interspan is going with TWO sparks, others up to 10 sparks.

a "standard " sparks is going by abouth 4.0 mill. sec.
abouth 10 sparks by CDI , each one fallowing the other by a wayting time of say 0.2 mill.sec. will fit this standard spark time.
I will try to go a other way to get a longer spark duration, a way wich is just to go for a single zylinder 4 strocker I would say.
- basicly I will use 3 ore more CAPACITORES to load and discharge to the ign. coil in a surtain time distance.
because, I say, time is the only thing we have in this quick game of needing 4000 sparks a minute only!

a other value it is deciding the spark time is the capacitores capacity.
usely, the capacitor of the CDI lyauts I have seen until now, they are by 1 micro farat.
using a 2 micro farat give a nearly double spark time I guess- but by loading this thing, it makes a heavy short to the transformer wich is producing the about 300 Volts.
this is the reason for me to use this POT CORE transformator type, it is symply the best one for this isue in my ayes.
saying this, I am not shure abouth, because I can not do al the calculations for it, so I do it "just over the THUMB" !
as I am searching for a lyaout for this charging - discharging now, I have orderet some Capacitores in sice of 1 - and 1.5 mic farat as to se
BSA1065.jpg
the good thing on a multiple condensor system will be, it is not heavy ,and as the capacitores do not get hot ad al in this game, for example 3 of the 1.5 micro farat ones do not take much space, only ab 5x5x3 centimeters.

so, I think, a other BUG ( IC ) will bringing me to the place to charge and decharge this steped capacitor system I hope....
( the charging of the capacitores could prabably be "streched" by a resistore in the line to each capacitore. is`nt it, minety ?? )

beat <216

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Re: It sparks by CDI

Post by Ian Hingley » Fri Oct 30, 2009 6:07 pm

Hi beat

How long a spark duration would one of these capacitors give??

Image

Cheers

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Re: It sparks by CDI

Post by Mark Cook » Fri Oct 30, 2009 6:43 pm

OH NO, not wima capacitors :!: :!: :!: When I was a nipper, if it didn't work you could blame it on one of those :!:
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Re: It sparks by CDI

Post by beat » Fri Oct 30, 2009 8:39 pm

Sorry, :oops:
this red ones are by 400V DC / 250 V AC, so I planing to use them for testing reasons only,
the BLUE ones are by 875 V DC / 600 AC.
it means, if the red ones will work ( if ever ) on the test bench , the BLUE ones should last at the bike fore shure .this mixed colors ones Jan is offering - I don`t trust this colore . I feel very unsave... I keep on blue... <928

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Re: It sparks by CDI

Post by eiranen » Fri Oct 30, 2009 11:38 pm

In many affairs blue is better than red! <217

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Re: It sparks by CDI

Post by rhino » Sat Oct 31, 2009 1:20 am

Blue is always better :thumb

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Re: It sparks by CDI

Post by Mark Cook » Sat Oct 31, 2009 10:43 am

I'm wondering about your theory on the capacitors Beat. Won't the capacitors just discharge as fast as they can trough the coil? So the time period will remain around the same? Is it possible to have a "long spark"? or is a "long spark" realy an arc? The other side of this, will a large capacity demand more from the oscillator? Will the primary wires be able to handle the current? I guess it could possibley try and draw AMPS!.

Come on Beat, I'm all excited now :lol: Can't turn out worse than the chain grease on the carpet :laugh

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Re: It sparks by CDI

Post by beat » Sat Oct 31, 2009 9:21 pm

hi mark,
as time the current "runns", is always the result of : capacity of energy and resistence on its way .

so, on the charging side , the loading the capacitores is jurely not in a hurry by 4000 sparks a minute, because the D-WELL ? ( closing time of the points ) is much longer then the sparking time of the plug wich is normaly only a hand full of crank dergrees. the other 350° are time to load the evan biger condensores.

on the discharge side , the result I hope to make it visuable with the osciloscope to se the difference , also the testing this together with different coils, say different resistance in the primary windings of them.

for the oscillator, it is shurely a biger work to do. but as I say, : the right transformator and the right resistance in the line to the condensores should cop with the "only" 4000 loading sequences a minute for a B50.

IFF I FAIL; THERE WILL BE SMOKE AND SMAL FIRE IN THE LIVINGROOM ; BUT NO OIL ORE GREASE ON THE CAPET THIS TIME :!: <925 <926

beat :laugh :mrgreen: :laugh

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Re: It sparks by CDI

Post by beat » Tue Nov 10, 2009 10:07 pm

hi al,
as I wait now for a first lot of parts to go in the practical made of this thing by using a electronic parts test plate, I would like to decide the targets I surch for:
- as first I will have a CDI ignition it stil runs on points and original timing advancing.
- as second, if this electronic systems fails, it needs be able to swich over to the standard ignition system.
- as third, I will reach a spark time of 1.5 to 2 ms ( standard is 4 ms )
- as fourth, it will not have al in one unit, no, - one unit will include the 300 Volt Power suply, - and a other will include the " forming the spark " only.
and ad last: I WILL HAVE SOME FUN BY DOING IT AND WILL LEARN SOMETHING BY THE WAY...... <965 <127 <017 <018 <059

so, the last vew days ( eavenings ) I was "producing" just paper, studing electr parts cataloges and "calculating" some values and layouts.
as I was starting this project around 30 years ago, I had to realise as not many partnombre from this passed time is stil in use, so it needs to search trough a lot of "unknown" stuff , because I have usely nothing to do with electronics. -
and I had to realise something more : not only the parts have changed, no, myself, I have changed two : I guess, I was getting older within this time <982 <906 <982

now a importand question : is it from interest to the one ore the other forum membre to se this papers and calculatings ?

as it is not shure this CDI will ever run, I will ad least giving this project a try...

beat

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Re: It sparks by CDI

Post by Mark Cook » Wed Nov 11, 2009 9:39 am

Yes post them Beat, you'll give pleasure to everyone.
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Re: It sparks by CDI

Post by beat » Sun Nov 15, 2009 9:44 pm

hi al,
the target was to know the time in milli-seconds and the resistor in ohms to charge a CDI spark energy capacitor.
my results of the time wich is avalable for full charging the capacitor ( 2.2 uF capacity in this example ) in a single zyl. by 10 000 rpms.
timecalcex.jpg
so, if I do not miss something, the result is :
by a time space for the spark of 0.002 seconds, it rests a loading time of 0.010 seconds, and this point is save by 10 000 rpms.
the RESISTOR to set in the load line should be 909 Ohms, say 1K ohm for charging a 2.2 uF capacitor.

a other result is the crank angle the flywheel is doing wheilst a spark duration of say 0.001 second ( one milli second )
by 1000 rpm it is 60°Crank,
by 10,000 rpm it is 6° only. (Edit by mm, added extra zero)

so, if this is al corectly , we can say, in high rpm`s as 10 000, a spark duration of more then 0.0005 second = 30°Crank is comleately useless !
in other worts, a long spark duration is only from interest in low revs as the starting procedure for example.
but evan in idling, 6 ore 10 degrees crank should be enough to get the stuff burning i guess. and this needs a spark duration of 0.0015 seconds ( 1.5 milli seconds )

this explanes why I do not decide my target for the spark duration time as long as a standard ignition spark is ( 0.004 seconds )= 4 milli seconds .

I hope you di`d not fall in sleep by al this numberings...
beat <907

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Re: It sparks by CDI

Post by Mark Cook » Mon Nov 16, 2009 9:53 am

Funny I've never thought about spark burn time in terms of rotation, you've got me thinking again :!:

First thought, I think you've missed a "0" out. From what I would expect you seem to have a decimal place error. Don't worry, on friday Gerry was getting lost between multipying and dividing :lol:
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Re: It sparks by CDI

Post by minetymenace » Mon Nov 16, 2009 2:43 pm

Assuming you are trying to set fire to the mixture at a certain time, it seems that you are trying to do this by making a continuous arc (or a series of individual sparks) starting at the set time. I would question if this is the best way to go about it as you don't know (without some serious dyno testing) when the mixture ignites. If I were doing this I would concentrate in getting as much energy into the spark at the set time.....in which case a few equations might help:

Q=CV for a full charged capacitor, but the charge on/in a cap/coil at a particular time in the charging cycle is a bit more involved.

The energy stored is equal to 0.5 x C x V x V, this is a more relevant equation because it shows you will get far more energy by increasing the voltage (its squared) than by increasing the capacitance....

A series of sparks, or a contineous arc will ignite the mixture when it is most easily ignited, as this may vary, and is not easily measurable, who knows what is going on...
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Re: It sparks by CDI

Post by minetymenace » Mon Nov 16, 2009 5:52 pm

Furthermore, if you assume that the mixture is swirling around (I would have thought it very unlikely that the compression occures in an even uniform way), there may be an advantage of and arc (or series of sparks) in that it would continue to ignite any unburnt mixture as it swirls around the source of the spark which otherwise would not have burnt.....but would this produce multiple flame fronts and the possibility of producing a detonation akin to a shaped charge which drills a hole in your piston....


.....Mark I have found some more measuring kit that should give a more accurate result
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Re: It sparks by CDI

Post by beat » Mon Nov 16, 2009 8:41 pm

thanks guys, it is always good, somebody is counting my calculations as well......!

abouth the spark energy : yeas, higher Voltage would be the key to put on a easy way more in to the capacitores, that is right.
but on the other side, the usualy given ignition coils are by a transmition of around 1 : 400 , so as higher the voltage on the primary wire ( the one from the capacitor ) as higher the voltage at the Hightension side, say on the spark.
as a standard ignition system produces around 20 000 Volts peak to the sparkplug, - a CAPACITIVE system , feedet with around 300 volts, produces around 50- ore 60 000 Volts peak to the sparkplug !
and we know, - only around 5 000 volts are used to keep the spark " running " on the plug for the 3.8 milliseconds after the short peak needet to jonisade the air fuel mixture in between the sparkplugs elektrodes ! this values are on a standard system of cause.
so, as the very high peak of a CDI is creating some problems, in my opinion, not a super high voltage is the target, no, I surch for a "longtime" spark. and my way to go there is by a multiple capacitores use.
I dont know how many caps I will fit, probably 3 ore 4 ore 6 of them to get to this target.

a perfect CDI system would be the one wich could run on a half a docend of the caps for starting, and by higher rpm`s it would run on less caps, because not needet anymore.
BUT SUCH A SYSTEM IS BY FAR OUT OF MY REACH !

so, I will be happy when I have sorted out a design for this " simple multiple capacitore use ", because as I breed over it now, the polarity of the BSA`s electricity by + to ground is making me a bit worry at the moment.... <988 <908
the reason is, I would like to use this MOSFET transistores to " fire " the capacitores to the coil, and it seams as the negative potenzial can not be switched by MOSFET`s :?:

minety, can you give a word to this Question ???? :?: :?: :?: :?:

beat <965

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Re: It sparks by CDI

Post by Mark Cook » Mon Nov 16, 2009 8:50 pm

How hard would it be to make it negative ground Beat? I agree about the high peak voltage being a problem. We have Standard and long burn Interspans at hand so when the workshop is quiet and cnc's and compressors are not shifting the mains voltage we will take some more accurate measurments. It will be interesting to see how the man gets his results.
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Re: It sparks by CDI

Post by beat » Mon Nov 16, 2009 9:01 pm

yeas mark, I think it would be easy to make - negative ground because I run a SPARKS generator, and the say it can be used for both polaritys.

the bad side on it is, my selfmade TRANSYSTORE System will not cop with reverse polarity then <125

so I have to test al out on my new SOLDERLESS BREADBOARD I just got it yesterday. <982
see wat is coming out on this one.....
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Re: It sparks by CDI

Post by Mark Cook » Mon Nov 16, 2009 9:46 pm

Don't put the beadboard in the oven, it won't rise. Making toast from it tastes terrible too. I've had mine for years unused. I bet the dust is conductive :shock:
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Re: It sparks by CDI

Post by minetymenace » Tue Nov 17, 2009 12:16 am

My point about voltage related to the storage of energy in the capacitor, not the coil. IF you doubled the voltage on the cap, you could of course adjust the number of turns on the coil to get the same voltage at the spark. If you apply DC theory to AC circuits, you will only get an approximate answer, and as the voltage and frequencies increase, so does the approximation but maybe it doesn’t matter.

Have you considered a voltage multiplier circuit rather than a coil........coil-less ignition, not there’s a thing.
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Re: It sparks by CDI

Post by beat » Tue Nov 17, 2009 7:11 pm

hi minety,
minetymenace wrote:IF you doubled the voltage on the cap, you could of course adjust the number of turns on the coil to get the same voltage at the spark.
yeas, I can see the point, but, do not forgeth : I " trust " the electronics not to much, - and my selfmade, I trust even less ! so this is why I will use a standard 12 V coil wich together with points and AAU alwais give the oportunity to swich over to something " known " !

I just spoke with my son, he (hopefully) will be the one is programming the IC`s. he sais, there is a possibilety to use more capacitores in lower RPM`s then in higher, so, this offers a new window for " saving " the 300V power suply by : 1. using different values RESISTORES in the capacitores feed lines,
2. having different spark duration for start up and low revs compared to high revs.
<017 <017 I think it needs some more paper.... <982

one importend point in this game is shurely the TRANSFORMATOR in the 300V PS.
I have found a suplyer for a biger POT CORE ( 47mm now ). but nowewhere a bobine to get for it.
so, this night, as soon as " al cats are black ", I will stay on a lathe on my pastaway workshop and made some bobines out of plastics by my own...
this bigger travo gives way for feeding more capacitores and / ore faster as well.
beat <216

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Re: It sparks by CDI

Post by beat » Tue Nov 17, 2009 9:40 pm

I have them,
BSA1066.jpg
BSA1067.jpg
the cats have been black enough and they fit nicely.
next step will be : wires winding on to the bobines
new sizes: 1.0mm for primary coil, ( bevore 0.8 )
0.4 mm for secondary ( before 0.3 )
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Re: It sparks by CDI

Post by beat » Tue Nov 17, 2009 9:53 pm

so, a (4. ) symple design of a multiple cap. layout shows this :
fireschema sixpackV4.jpg
hey minety, can you check the polarity of the DRAIN - SOURCE , GATE conection for corectlyness please :?:

beat <201

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