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It sparks

Posted: Sun Jan 28, 2007 8:59 pm
by beat
nearly finishing my Transistor Ignition soon. it works on my testbench so far. nextly fitting it in to the housing for corectli cooling, so it will be to compair with the standard Points-Coil - Ignition by osciloscope.
if there is a interest of details by some forummembers let me know.

Posted: Sun Jan 28, 2007 9:12 pm
by chobbler
Im interested, I'm messing about with Hall effect sensors at the moment.

Posted: Mon Jan 29, 2007 2:16 pm
by Mark Cook
Nothing better than having a play, but for trouble free ignition there is only one.


Well I just had too :lol:


Posted: Mon Jan 29, 2007 4:10 pm
by Ed V
C`mon Mark!

Posted: Mon Jan 29, 2007 7:43 pm
by chobbler
What's that Pazon company all about? Never heard of them before.
Boyer, yes, but Pazon..

I have an old SR500 cdi box I've opened up for a look, that and some spare sensors got me thinking. :???:

Posted: Mon Jan 29, 2007 7:50 pm
by Ed V
Chobbler, From what I understand Pazon is a couple of the guys that were at Boyer and went off to do their own thing. I gather that their ignition will fire at a lower voltage than the Boyer but they are also more expensive.

Posted: Mon Jan 29, 2007 9:50 pm
by beat
as I said in Parts Wanted-selfmade Transistor - switch, this is a ignition to give mainly the points a mutch longer live.
it is not made for higher performance ore to make a ritch man out of me as Mark it is by selling houndrets ore evan tousends of his Interspan Systems..... <029
the costs are also different, the materials itselfs are less then 10 Euros if you can grap the stuff for the housing out from the rubbishbin as I have done.
so coming out soon with some more, fore the ones they like it a bit more exactli they will find the tecnical data for the Motorola NPN Silicon Power Darlington Transistor MJ10012 by Alldatasheet <018

Posted: Mon Jan 29, 2007 11:21 pm
by HPbyStan
I still use points on my race and street B50s. I use 305 H*nda Super Hawk points that were happy to 10,000 RPM on a H*nda and a Dyna Ignition Booster along with / or in place of the condenser and a Dyna dual lead coil. I think dual lead coils fire one plug in one direction and the 2ed plug in the opposite direction.. Back in the Day we used to buy a H*nda dual lead coil for the Gold Stars and ground one lead thinking that the spark would be trying to jump in both directions. The Dyna ign booster takes a lot of the switching work off from the points and they last forever.

Posted: Tue Jan 30, 2007 9:56 am
by Mark Cook
Get rid of the current handling of the points and that makes a whole lot of differnce, I remember reading techniqal journals from the sixty's showing circuit diagrams using the new power transistors. I guess now the thing would be to use a FET. Even interspan do a system that still uses the points, to me this is pointless. Please don't let me put you of experimenting.


Posted: Wed Jan 31, 2007 12:24 am
by Ed V
Mark, If it still uses points how can it be pointless? LOL


Posted: Sun Feb 04, 2007 8:31 pm
by beat
part 1: try to explain what I am doing for the spark on my B50
the target at this time is, to have a ignition system witch is giving the points a mutch longer live and witch is possible to switch over to the standard ignition system.
I have started this project abouth 28 years ago when i was living in a bit
ugli narrow circumstances. at this time I made as first a litle testbench where on a set of points are driven by a regulated el.motor (from a scrap sawingmachine) up to a vew tousend rpm/min.


then I use two variabel power suplys, two multimeters and two oscyloscopes. further I had to pas through a vew books and broschures and many talks with some "ignition-experts". ( why this is importend I explayn later in a chapter IGNITION FILOSOFI).
the wiring layout for my simpel transistor ignition loks like this :


at the left it is to se the points, nearby the condenser and below one polarity of the switch S. at the right it is the my coil, a nipondenso from a toyota corolla year 74 witch takes 3.5 amperes by 12.4 volts. between the two wireconections at the coil is a bypolar zennerdiode of 376 volts type BZW 376 B. it is fited to eliminate higher plus-voltage coming outh of the coil wile sprking. at the right is to se thesecond polariti of the switch S.

this is switch S with the maynswitch for the bikes el. below.
left oft the coil is a wireconnection, a fault of mine because switch S should be a 3 pole version witch I do not have at this time.
at the lower half of the layouth we se at left the resistor R1 witch has 27 Ohms and is a 5 watt type. he reduces the voltage to the BASE of the transistor down to 2.04 volts and the current to 0.375 amps. so the point has to switch only this 375 milliamps by 12.4 volts.the signal on it luks like this:

the length of the signal says nothing, because this is taken by abouth 1200rpm and my points and cam on this testbench are from a harley davidson.
so 0.375 Amperes in stead of 3.5 amperes, this will keep the points clean
they will hold for ever.
next to the resistor R1 is a other zennerdiode type BZW 5v8 witch has the job to make shure there is never a higher voltage on the BASE conection then 5. 8 volts. bycause a higher voltage then 8 volts will distroy the transistor.
The transistor MJ 10012 is to se here on his datasheet


as is to se on his wiring diagram, both of his darlington -steps are already
conected to minus for fast swithing off and a diode is already integrated.
as to se he can handling 550 volts in the COLECTOR- EMITER line, so this zennerdiode of 376 volts are maybe not necessary, but i have fited one more nearby the transistor for savetyreasons agayn. so this ignitionpart looks like this


finaly I put some glue as araldit over it ( heatem up in a tabelspoon first for beter running and faster hardening )

edited by Rickard

Posted: Sun Feb 04, 2007 9:17 pm
by b50root
The page doesn´t like ü and spaces in the filename!!

You can remove the dubble posts.


Posted: Sun Feb 04, 2007 9:51 pm
by beat
thank you rikard ! I try tu keep the ü and outh.
ath the end it loks like this




one word to the standard signal at the points :
by sparking, the induction of the 12 volts - 3.5 amperes in the primary windings into the secondery windings by a usual relatingship of abouth 1 :100 transforms the voltage up to abouth 15`000 volts. the result are also backcuplings into the primary windings of abouth 450 volts and it loks like this


this is what abuses within 10000 km the points. with the zenner diode at the coil


the signal loks by running the standard ignition like this


so, for today I think it is enough. the descripted target at the beginning is reached and I hope you d`ìd not fell in sleep by this explanation. :mrgreen:

Posted: Mon Feb 05, 2007 9:52 am
by Mark Cook
It's nice to see people exprimenting and doing what looks like a very proffesional job. WELL DONE BEAT :grin: As for me selling hundreds of interspan units I don't. Too expensive lol. I guess total sales, based on the metal work that I make would be about 150 - 200 units a year. Over half of these would be for speedway. Nothing works as well on a wet methanol engine. (would be cheaper to use a smaller main jet!)

How about an even simpler idea, Briggs n Stratton. No points, just one coil and it sparks??


Posted: Mon Feb 05, 2007 11:27 am
by minetymenace
Very good Beat, nicely done.

I think you are half right about the zenner. I dosn't need to be bipolar (a diac), an ordinary zenner would do (if you are worried about overvolting the e/c junction) because of the sacrificial diode in the darlington.

Will you be going for an electronic advance and retard next?

Posted: Mon Feb 05, 2007 11:50 am
by beat
hy mark, I do not know the Briggs&Stratton ignition but the simpliest system I ever have seen is the Piezo- ceramic System.
a system where a springloaded "hammer" like the points get lift up by a cam witch has a overhanging side and is nocking on a kristal-cube. this cube gifes in result of this short high mechanical pression a el. tension witch ocures as a spark at the sparkplug.
one importend thing : SPARK and SPARK is NOT THE SAME !!!!
and it depends hard on your demand,- do you wanted to have a "save " system and longlive, ore du you wanted a system witch is made up for highest spark energi and voltage, as for exampel the HKZ ( Hightension- Capacitive- Ignition ) witch is also known as the Thyristor ignition.
abouth the spark energi I will give my expirience soon, one thing is for shure : TO MESURE THE ENERGI OF A SPARK IS VERY DIFFICULT AND FAR OUT OF MY REACH.
so al promises on sales brouchures are the same as "wind and clouds" and " guess and beleving".

hope you can sell a other tousend of your interspans and the content owners of a system are still the best comercials. <038

Posted: Mon Feb 05, 2007 12:33 pm
by b50root
minetymenace wrote:Will you be going for an electronic advance and retard next?

That must be next step for Beat. :lol:

Thanks Beat realy intresting to see what you are doing.


Posted: Sat Feb 10, 2007 8:39 pm
by beat
part 2 : sparks energi & filosofi
I would like to compare my two ignition - systems, descripted above, here in view of the sparks energi. it is easy and fast to do on this little testbench. Image

time is in this case importend because the coil is heating up in use and is clearli consuming less energi in hot condition.
so , by same condition the original ignition consumts in my case by 12.4 volts a current of 3.50 amperes. witch is a energi of 43.4 watts. this is with points and capacitor in best condition !! some of this energi will not be inside the spark in the combustionchamber, because by opening the points is also a smal sparc ocuring and also the capacitor takes some energi to avoid a biger loss at the points. I dont know how mutch this is but I guess it is inside of some percent. ( Minety, did you have a idea how mutch it is ?)
so, by same condition my transistor ignition takes by 12.4 volts only a current of 3.40 amperes. and we know that from this 3.4 amps already there are 0.375 amperes are passing by at the points. so this is clearly
0.475 amps less ore 13.57 percent less.
intrusting, is`n it ?--- so where is the sens for a electronic ignition system if the spark is by abouth 10 percent weaker ?
so,Filosofi, and practical influences...
at first the points. they will not remayn as new, by 5000 ore 8000 km they are not flat enymore so they opening not as fast as new cause of "hills" and "vallys" they grip like teeths in each other and the distance of 0.35 millimeters is not reached that fast. by this situation is easely energi to loose in a reach of 20 to 40 percent as some experts says !! this is especialy to feel by kikstarting the engine where the opening of the points is the slowest anyway !¨also I have made this experience of bad starting bike cause of wornout points.
at second the capacitor. difficult ore impossible to check, but also he can have a negative influence for the sparks energi in the standard ign. syst.
FILOSOFI : a transystor ignition system has a smaller spark energi then a stand.ign. syst. in his best posibel condition I say.--- this only by the circumstances as both are running with the same coil !!
please Minethy, help me if I am wrong !!

Posted: Sat Feb 10, 2007 9:58 pm
by beat
part 3 : the future ;-)
as we know, the points are not able to switch higher amps then max 5 amperes, ore they will be abused within 2000 ore 4000 kms. not intrusting I say.
different the transystore : hi is abel to switch 10 Amps withouth any problems and any abuse for we say 500 000 kms. ( haw old I will get ? )
so what I am loking for is now one of this "highcurrent coils" witch are used by this systems, but in view of the BSA`s generator not a too highcurrent one, abouth 5 ore 7 Amperes would be ok. so this will compensate the 14 percent loss by far.any tips ore partnumbers are wellcome....
a question at stanly : can you tel me the H*nda- partnr. for the points as you say you are using a vew days before please ?( Jan. 29 ) thank you.
so my next project will not be the timing advancing because of never had any problem with ore replacing the points by somethings electronic, no, my next project looks like this at the moment
it is a total experimental- poorly firststep - prototype of a HKZ working with a Thyristor. ( in this case NOT working :oops: <022 at the moment )
I hope to finish it next winter...
the reason of it is this :
1. by using a highcurrent coil it is only in high emergency advised to use the switch and runn the system in standard ign. ( abuse of points and danger of braking the capacitor because this coils have also almost a transmition ratio of 1 : 400 abouth)
2. the hightension capacitor ignition has a sparkvoltage of abouth 40 000
volts ( compared with abouth 15 000 the stand.) by using a standard 3.5 amps coil.
so the switching over to stand. ign. should not be a problem.
well, soon is coming springtime, I hope , and I work on a totaly other project now witch will be also fited on the B50 sometimes. ( sometimes only ! ) no picture at the moment...

about the zenner diodes i have used, the bipolare ones are especiali made to protect elctronic components as they say and for me they are excellent because I can not fit them into the circuit the wrong way
the osziloscopes are both 2 chanals, but the handling of my is not that experianced.... <009 <121
thanks for the offer to help with some parts and ideas minety, I guess next winter I will come back to this offer...
wishes al of you a nice sunday
beat <069

Posted: Sat Feb 10, 2007 11:25 pm
by Bill
Beat, remember the transistor junction will have at least a 0.6-volt drop across it even when fully saturated, so that may account for some of the loss. You could increase the supply voltage to compensate, then test and see if the currents are the same.

I would expect the coil to take a bit less if the voltage is less, you could use a 6-volt coil and put a ballast resister in to compensate, then set it up to run say 6.5 volts at the coil when running.

Also an advantage with a ballast resister set up is that you can short it out with a switch for emergency starting when the battery is low.

Just some thoughts


Posted: Sun Feb 11, 2007 10:31 am
by bsamxer
many years ago I tried a 6 volt system on a cheney B50, nice small coil
light wieght battery from a modellers shop, still with points and condenser,
advance controlled with the standard bob wieghts. I played around with the advance with different backing plates, weights and springs.
BSA made several different advance plates and stamped them in cam degree's, 3, 5, 7 so you double the number on the plates advance to get crank degrees. For motocross you can use a lot of initial advance and get the total advance in quick obviously allowing for detonation due to too much advance. 30 degree's seem's to be about the limit, 28 works well.
But with all forms of racing you don't have to worry about cruising or fuel consumpion.
I managed to get the B50 running well and I was pleased with the performance, one battery lasted over six hours and I had a spare!
The whole set up cost under 20 pounds and worked well.
Roy Davis persuaded me to fit an Interspan from fred stoneman and the difference was amazing, with no other changes it performed like a different engine. most noticable was the bottom end which with bigger valves,ports and better cam had got a bit soggy for want of a better word.
With the twin plug set up its even better. So I will sing the praises of fred and interspan, but then from fred at 250 pounds it was a must have, now I think the price of the units is at best restrictive to say the least.
Beat, if you can come up with a functional pick up, and advance unit to work along with a good alternator, more power to your elbow.

please note no 'slang'

Posted: Sun Feb 11, 2007 10:51 am
by beat
you are right bill, I know the loss is coming from this physicaly circumstances of the transystor witch is belonging to the famili of the semi- conductors. luky it is a bit more then semi, abouth 86 percent witch is still passing trou.
some modern FET would be beter probably but i like it the sympli way.
the saturation voltage I have decidet as fallow : took my two adjustibel powersuplys, conecting the minus together, seting 12.4 volts at the Emiter- Colector-line with the coil as the load and giving rising voltage with the second powsup. to the Base. it seams for me that with 2.04 volts and 0.375 amps it reaches a good saturation, so I can runn hopefulli also a 5 amps coil witch I not have at the moment on it.

<119 for my, the importend thing is as fallow : a electronic ignition witch is not including his own especialy coil has a lower spark energi then a standard BSA ignition with good condition points. unless I miss something.
EXEPTIONAL it is a HKZ witch is working different.
so if the salesbroschure is not giving the right information abouth some
" secrets" of the system, al this promyses of - SAVING FUEL, HIGHER PERFORMANCE, HIGHER RPMs, MORE SUNSHINE and BETHER SEX are only tru if you compare with abused points.
the BETHER STARTING I will agree, but the rest is not tru. <001
:idea: I do not wanted to make shay eny people to buy a modern electronic system,no. but it should be posible to know a bit more about it bevore you buy a "black box".

as some books and some experts say, a engine is running with a spark of abouth 7000-8000 volts already. the starting the cold engine is the bigger problem, caused by bad moistering of the mixture ( big drops of fuel).


so, to spend a little monay for your B50 is one good thing,
to have a engine witch runns a bit bether is a other ,
to know inside of you : IT IS GOOD WHAT I HAVE DONE
this is what is making me and you happy !

:thumb <200 <208 :ok :lol: <012 <055 <222

Posted: Sun Feb 11, 2007 11:22 am
by beat
thank you paul for " no slang " and intrusting "ingredients".
I have andestand abouth 95 percent of it. ;-)
as I say : happy customers are the best comercials !
there are good systems of cause, but they include a vew things and they cost a bit of monay. and it is ok. like this. <1

Posted: Mon Feb 12, 2007 1:29 am
by beezergeezer
<216 Beat----- I don't know if this is of any worth or not; but------decades ago, I had a 1967 Ford automobile with a high performance engine that was factory equipped with a transistorized ignition that sent power through the points BEFORE going through the coil. Purpose being not to send super voltage through the points. I have no idea how or why it worked. Possibly someone out here could enlighten. Good luck. Beezergeezer. :grin:

Posted: Mon Feb 12, 2007 1:16 pm
by Mark Cook
Ah geazer, you beat me to it. I was going to suggest an amplifier stage after the switching device.


Posted: Mon Feb 12, 2007 1:23 pm
by minetymenace
Am I missing something? The points are used to switch the darlington pair, the Darlington IS the amplifier stage. Nowhere do you switch the HT, the switching is all on the 12v side..... :neutral:

Posted: Mon Feb 12, 2007 1:38 pm
by Mark Cook
Ooopps :oops: I forgot Beat was using a darlington set up. Still puzzeled by the aparant loss of spark energy. Come on then someone. An easy way to measure spark energy, not by calculation. A comparitor of some sort? Air gap can be used for spark voltage, but puts a strain on the ht insulation.


Posted: Mon Feb 12, 2007 8:06 pm
by beezergeezer
<216 Ref: "measuring spark intensity/ampreage........stick it to yer tongue, Mark.....intensity is directly proportionate to the amount of time it takes to un-cross yer eyes ! ( howm I dooin, guys ? Geezer. :grin:

Posted: Mon Feb 12, 2007 8:27 pm
by beat
<124 hy geezer, did you check a spark with you tongue just before you have been taking your photograf as to see in your mails ??? <130

Posted: Mon Feb 12, 2007 9:09 pm
by beezergeezer
:roll: Nope........-picture was snapped during a private moment involving bowel function, thankyewverymuch!

Posted: Mon Feb 12, 2007 10:48 pm
by Bill
Beats test rig is nearly there, stick the spark plug in an enclosed box with a photocell to measure light via the oscilloscope and see which one is consistently brighter when running flat out on the little test rig.

Wont measure any know standard but beat could name them as "micro beats" uB's

1 beat = to a 1 watt bulb in the same enclosure, and uB's to be measured on a champion N3 spark plug (New world standard)

:mrgreen: :mrgreen: :mrgreen: :mrgreen:


Posted: Tue Feb 13, 2007 7:22 pm
by beat
I guess you are right bill, the light of the spark would be the realy thing what would give the right way to the energy. but as I say : such a instrument is far out of my reach ! ( shurly the reach of my salery <218 )
as I do not stay in a time of fortune at the moment, I have punchet heavely my right hand last night. ( working nightshift ). maybe I should beter develop a skin-sewingmachine, it would save me this time from cost of the hospital and the doctor. <125 <022 <010 I think need some especialy medicine for the coming night <030

Posted: Wed Feb 14, 2007 12:02 pm
by beat
hy bill

abouth the 6 volt coil solution, I d`ont like it very much, because of the resistors energy wich will be lost. if this could be used as a grip-heater on the handlebar, so ok. ;-) , but it makes a bit a long wiring inside the ign. system...... :???:

inside my head I am fiddling around on this HKZ, where it should be possibel to decide by my own haw much energy it will consump, so it is in a good balance to the B50 `is alternator output. <052

Posted: Wed Feb 14, 2007 12:13 pm
by Mark Cook
Beat, Gerry was on about the spark energy being the voltage x the decay, so I guess if you calculate the area under the curve you should get a comparable figure.

Do you know what I'm on about, I'm not sure. I should have payed more attension at school lol. :oops:


Posted: Sun Feb 18, 2007 8:04 pm
by beat
hi mark
as calculating was never my strongnes in scool nor jet, I am simpli unabel to do it. <051
so I try to make some pictures of the hightension sygnal to compare the systems just by visual comparing.
but it needs some time..... <127

Posted: Sun Feb 18, 2007 8:29 pm
by Mark Cook
I'm a silly sod Beat :oops: Just put a resistor in the HT line and measure the voltage drop across it. And just for lazy people like me, this is handy


Posted: Sun Feb 18, 2007 9:23 pm
by chobbler
I heard the Italians are using a double spark on their big twin two plug heads.
But not at the same time. The first spark is followed by the other a fraction of a second later. One of the two is the standard map (still variable) the second one's timing is even more variable on load/ revs /temp. I suppose if the timing is right that would fool the burn into behaving like one long fat spark?
I think it's by Minarelli or something.
I wondered how you get 150+ hp out of two cylinders.

Posted: Sun Feb 18, 2007 10:02 pm
by Mark Cook
Ah ha Chobbs, the interspan isn't actually a single spark ;-)


Posted: Sun Mar 04, 2007 9:58 pm
by beat
surching for days my selfmade 1 : 1000 probe to do the HIGH VOLTAGE mesurings. it is unbelieveble how big a smal house can be....
so it is interesting now to see where is this difference of abouth 10 percent of energi loss by the transystor ignition.
first picture is the212 is the standard coil ignitionImage
the second is the transystor ignition, compare the time ( the length ) of the
middle horizontal part wich is abouth 3.8 milli seconds.
this part is realy a bit shorter by the transystorysed spark !
for my it seams to be a smal loss of somewhere of 0.2 mill. seconds of the spark time. I think this is not to worry abouth.
interesting also howe the same spark looks different on a older analoge
so with this results I think I will finish for the moment this chapter.
the target set on the beginning is reached, and the next one, this CAPACITIVE ignition, I guess will start next winter. <217

Posted: Mon Mar 05, 2007 1:04 am
by minetymenace
Interesting Beat.

I think the ringing is due to calibration of your home made probes, do they have any adjustment on them, how did you calibrate them?

Is this a measurement taken in a "real" engine, or is the plug on a test bench in free air?

Are you using the probes in differential mode? Is the scale realy 1kV/div? How wide was the plug gap? (You might try increasing the gap and see what difference that makes)

Did you manage to measure the HT current?

Keep up the good work, but if you have to ride your bike untill next winter comes, that is no great loss!!