It sparks

[minetymenace]

If you feel like designing some smart electronics, how about a rectifier/regulator with a FET bridge front end that will regulate and rectify with maximum efficiency at all frequencies, possibly with a boost converter to charge the battery even at very low rpm. It shouldn't be too hard to produce a separate pulsed output for a tacho, and if it is really clever you could look at the ac input and determine the crank position. It's too cold to work in the garage (unless you have a B50 basement like beat!!)

[hwan]

I'm not criticizing BEATS work at all, good for him.

As i said i enjoy playing with electronics, and there was an easier and potentially less temperamental solution than using 555's and transistors.
If you regard microprocessors as being 'smart' - then I'm sorry, its a damn sight easier teaching spotty 13 year olds digital electronics than transistor and 555's - and they are anything but 'smart'.

As for "rectifier/regulator with a FET bridge front end that will regulate and rectify with maximum efficiency at all frequencies, possibly with a boost converter to charge the battery even at very low rpm" - why reinvent the wheel, there are enough devices out there, or fit a higher output stator and/or reduce your power consumption.

What there is a shortage of, is a reliable circuit of a simple programmable ignition system since the demise of the EPE/JAYCAR offering a few years ago.
Yes i have been dabbling with adjustable advance curves, but sadly the picaxe micro's i've been playing with are not fast enough and i haven't had the time/inclination to relearn another programming language.
I recently started looking at this problem again and have purchased back copies (EPE SEPT/OCT/NOV 2009) - simple enough circuit, again based around a micro and includes the program (in 'basic') - i just need to finish a few other projects before moving onto this ..................

[beat]

beat is trying to make a small electronic device that will remove the power switching from the points to make them last longer, boost the spark, and be able to ditch the electronics and return to points/coil ignition if he breaks down on the road. It also has to run at low voltage, be blue in colour and keep him entertained during the cold Swiss winters.

EXCELLENT sayd Minety !! ( as far as I do understanding it

and in oposite to many others

i just need to finish a few other projects before moving onto this ..................

mine is already finished:

tested and covered the electronic parts with Plastidip

unlucky NOT in blue color..., but at least it is not a completely " Blackbox ".

when wetter will allow it to work outside where the bike is, it gos in to the circuit and yes, I am planing a " extendet " weekend this year.
the direction willbe West, Northwest, somewhere around Mai / June. ( France , England, maybe Scottland )
then the unit could show is it running ore not.

but first, I go a week snowboarding now, hope my old boons keeping as sorted in original.....

beat

[skippy]

Good luck with the snow

[hwan]

BEAT - don't reduce current across points too low - there needs to be around 100mA 'wetting current' to keep the contact area clean - this is standard is practice on all contractor based systems operating in a normal (as opposed to an inert) atmosphere.

I swapped to a sealed (vacuum) micro-switch and eventually to hall and then optical switch after getting random contact closure on a VW distributor based system - i then realized i had gone too far reducing switching current (i was down around 5mA), hence other methods of switching.

I'll try and find, and photo the model airplane circuit i used in 1979/80 - that was a simple transistor switch operated by an optical device and it survived many hours of 10cc induced vibration around 10,000rpm.
Not my design, something i got from an American Model Mag, worked on a 50cc chainsaw engine as well.

[beat]

don't reduce current across points too low

I know this hwan, my current is 440 mA at the points by onboard Voltage of 9 to 17 Volts.
down at 5 Volts onboard it is still 290 mA.

( from 5 V to 9 V it is something in between )

beat

[stew79]

beat, whats wrong with cdi ? loose the point altogether ?
stew

[beat]

hi stew,

comparing cdi with inductive coil ignition I guess you are asking , right ?
no mater how to triggering it, - points ore sensors pickup, - both is possible for the one ore the other system, - no difference at this point.

the difference is mainly at the spark duration:

cdi : 0.2 milli seconds, ------- inductive: 4 milli seconds

so, a cdi spark is 20 (twenty ) times shorter than a standard old fashion BSA coil ignition spark !

now, you may say : how can be somebody this stupid to use a cdi spark if it is 20 times bader than a inductive spark, right ?

the answer you have given ( partly ) by your self when you have said: " the chinese coil is not as good but the engine runs same fine "
ore lets ask: how long a spark duration is needed to have a engine running nicely ??

the answer to this question is not so simple to give, but I will try:

speaking from a single zylinder engine:
-- for starting the engine ( ca. 120 revs a minute ) a spark duration as long as possible is surely the best, = good for inductive
( remember: mixture is NOT ideal, droplets are to big usually because oldfashion choke ore thickler, cold combustion chamber.)
the ignition itself: -- inductive, -- it consumes around 3 Amps, makes the battery may drop in voltage ( if not in good condition ),
spark is getting weak, = drop in spark duration = bad for the inductive.
-- cdi, -- it consumes just a friction of a second around 4 Amps, then the full spark of 0,2 ms is ready. nearly no load for the battery at all. good for the cdi
the question is : dos the short spark find some mixture in the area of the plug, - if yeas, it fires up, if NO, it needs a few more trys.
= bad for the cdi

for engine in high revs ( around 8 000 )
a spark duration longer than 6° Crank is a total nonsense, because if combustion starts by the end of this 6° , it will be noticed as a misfiring, a good part of the combustion is exhausted in to the pipe.
now, how much is 4 ms in crank ° and how much is 0.2ms in crank °
if you calculate this, ( I have done it, - it is somewhere in a topic here ), you will find as it is a plus for the cdi !

this are just two things are pointed out on the all process, there are some more of cause.

there is the question of: why modern engines using mostly the cdi ?

I say: they all are mixed with a fuel injection system, good spray nozzles are common,combustion chambers are optimiced, length of inlettrakt is in ideal lenght.
so a spark duration of 0.2ms is enough. = big plus for cdi

now, our old B50, long stroke, short intake, low revs usualy, carbis as per ANAL - the plus for the inductive is the main value I say.

but never less, I work myself on a CDI- still keeping the points as the trigger - just as a hobby in cold wintertime and be wondering how mine will do it ( if I ever get it running )
using a Mikuni Flatslide and a Lambda Sensor for fine-tuning the A/F Ratio.

this is my 1/2 cent opinion about it, ( 2 000 bucks spend in tools and parts in reality :)

beat

[stew79]

hi beat, thats a good explanation, but there are still 2 points (ha ha) i need to ask. first about the spark time factor for cdi, what data is this based on ? i have had many discussions with the boffin in oz about this. apparently most data is from trying to run the cdi system with a car type mdi coil. this is totally wrong ? it would be like trying to run an mdi system through a cdi coil , how good would them results look ? also cdi,s sparks more than once, so however many actual sparks occur need to be taken into account for the time factor. (its looking better for cdi already !) second why still use points ? isnt this a week link with lots of variables ? there are several electronic ways to replace them which have only advantages ? the main things are less parts, smaller, lighter, can easily be varied, (degrees at what ever speed etc) or even the old H*nda system that keeps the mechanical adv ret (with a small magnet in the end, the pick up coil reads the change over point from + to -)
stew

[beat]

hi stew,

now, how much is 4 ms in crank ° and how much is 0.2ms in crank °

just let us finishing this little job first:

when the engine is doing 8 000 rp/ minute, it is doing 8 000 X 360 ° = 2 880 000 °
makes in one second : 2 880 000 divided by 60 = 48 000 °
makes in one millisecond: 48 °crank

so, a inductive spark of 4 ms makes 4 X 48 ° =192 °crank
192 ° minus the full advancing of 34 °bdc makes a last chance for the beginning of the combustion by 158 ° crank after tdc.
dos not the exhaust valve opens by around 100 ° after tdc ???
( lucky the magnetic field in the coil find NO TIME to build up completely by 8 000 rpms, so spark duration is about 30% shorter ! )

a cdi spark of 0.2 ms makes 0.2 X 48°= 9.6 ° crank
the fully advanced 34 ° minus the 9.6° makes a last chance for the beginning of the combustion by 24.4 ° before tdc !

if I do not miss something important, we can say the standard inductive spark is clearly TO LONG in Time by high revs.
at the opposite, the cdi spark duration is nearly IDEAL by high revs.

Ähhm, - how was it by the startup revs of kicking it over of 120 rpms ??



will come to the next questions tomorrow, - please note: beat has not be eating the only truth

[stew79]

hi beat, you like keeping me in suspense, but were dose 4 amps come from for cdi power ? i can start and run a bike up to 4000 rpm powered only from one AAA battery ! (only up to half throttle, as not quite enough power to keep the spark strong) this is powered from a collection of bits from the old "tessla" box of electronics. (i made my first coil winder when i was 12, but since the web thing i have found so much more information about this fascinating subject ) if i use the two pole alternator on the ccm, instead of the 1.5v bat, it will start sparking ( 6mm) at 60 rpm. this is about as slow as the pick up can detect the timing. efficiency is the key to power. whether its carb, ports, compression, cam, ignition, spark plug, exhaust system, general mechanical condition, it all must come together just right. just about running and ride able, to running really well is an enormous step.
stew

[beat]

hi stew,

there are still 2 points (ha ha) i need to ask. first about the spark time factor for cdi, what data is this based on

I would say as the date where it is coming from is not so important as the storage capacity and the level of voltage in combination to the resistance in moment of discharging the capacitor ( C/V/R ) is making the time where the spark is alive.

no matter 30 years ago ore today, - a 1uF Capacitors charged up with 400 Volts, discharged by a Transformator with primary windings R 0.5 Ohm is mainly giving the time, yesterday, today and tomorrow.

apparently most data is from trying to run the cdi system with a car type mdi coil. this is totally wrong ? it would be like trying to run an mdi system through a cdi coil , how good would them results look ?

two questions, - let us do one by one.
running a cdi with a inductive system coil.
yes it works,- the inductive coil has a Resistance on primary by around 3.8 Ohm, the windings ( prime to second.) are in a relation as it will result in a to high voltage peak on the plug, - danger of problems at the HT lead and plug cap.
- the cdi coil ( wich is working actualy as a Transformator !! ) has a Resistance of 0.5 Ohms only and a lower relation of primary to secondary windings,
a voltage peak of max 25 kV is enough, the " coil" ( Transformator ) is much smaller than a inductive coil.

it would be like trying to run an mdi system through a cdi coil

this is a quiet bad a Idea, because the points have to cop with a electrical load of ( 12 Volts : 0.5 Ohms ) = 24 Amps
they will not last long
and a Pointsbooster ore Transistore switch called box will not survive exceptional the Transistore is from a Type of around 35 Amps on the C-E line AND
the Base current is set to switch this enormous energy
BTW a energy of more than 280 Watts, wich is more than the B50 generator is bringing!

but were dose 4 amps come from for cdi power

I sayd

it consumes just a friction of a second

a short peak the cdi is consuming 3 to 5 Amps to charge the capacitor of 1 ore 1.5 uF, - as I do trying to build a cdi with a capacity of 4 ore evan more C, it needs a " stronger" machine to load this caps.

why still use points ? isnt this a week link with lots of variables ? there are several electronic ways to replace them which have only advantages ?

ha ha ha,
the question should be: " what do we need on a single B50" , NOT " what is all aveable "

IMO, a set of points , used on a single , max Revs 8 000, THE ELECTRICAL LOAD TAKEN OFF ( reduced from 3 Amps / 160 Volts aver. down to 0.5 Amps 12 Volts ) will last for the next four humans generations.
and if the owner is able to keep the heel lubricated and the points contacts clean, points are doing the job just perfectly

hope you still find a sleep tonight....
beat

[stew79]

Best Electronics Advisor There is or beat for short, c/v/r stuff i understand (to a point) but good coil / bad coil ? when is a coil a choke ? an mdi coil dosnt like high frequencies a cdi coil transfers its power better (thats why they are different) if you had the best cdi system (any inerspan) and ran it with a car type coil it would loose most of its power. (things not balanced) on my test rig i have compared many coils. with the same power going in, the energy coming out can vary by 70% . i have made some interchangeable bobbins for primary and secondary, with several different cores. over the last 2 years i have wound many different combinations of turns and thickens of wire, looking for what works better. last year with help from OZ i can look at the results in far more detail on the scope. since then i have re visited all these old bobbins and re wound most of the several times again ! how long the spark last for can vary by a factor of 4. (some times maths and equations will only go so far, results from experiments are visible) the bit about mdi ignition through a cdi coil was only to make a point that they were not made for each other. most cdi coils i have tested tend to make far too many volts, hard to get a reading as when the spark gap gets too big (over 50mm) they short out through there bodies.(spectacular but of no use) 4 amps? yes i read that wrong, but cdi from a battery is a steady small drain. my AAA battery is only 1.7 amps (shorted) but its voltage then is only 0.15 v so how can it run the cdi ? as for the pionts, that a great comment about needing the bike in the first place ! totally get it, good luck with your ventures in this subject, and thanks for your reply's
stew.

[stew79]

forgot some pictures

[beat]

it looks very good, your winding - and the test bench

good coil / bad coil ?

well, each system works good with its designed coil, - the standard inductive ignition with a storing and transforming coil
and the cdi with a transmit and transforming coil.
they should NOT be mixt for good results.

BTW, if there is not a low voltage shut off device in a electronic ignition, they work mostly down to something 3 ore 4 volts supply.
but exactly this low voltage is it that killed the electronic on many occasion without been realized.....

[stew79]

hi beat, thats the point i have been trying to get across, published test results for all ignitions are all made with mdi coils only ! they dont test a cdi ignition with a dci coil ! as for shut off voltage ? the little oscillator (the square thing in the picture of the test bench with the blue cap across the input) has only got about 5 components on it ! it starts from 1 volt and will run quite happily with 30 volts. (its the simplest one i have ever made if you want i could give you a circuit diagram.)
stew

[skippy]

and the rest of as well?

[stew79]

gday skippy, what do you need to know ? what do you want to achieve ?
stew.

[minetymenace]

what do you need to know?

stew79, assuming you are not doing this for a business, but just for your own interest: Everything.
Publishing your own observations and results (here for example) would enable all to benefit from your toils and critical review from your peers may direct and enlighten your future work. There are some very clever people here that can assist, and even more not so clever people who are willing to learn.

So for the greater good, please consider starting a new topic and sharing your knowledge. An ethos that is at the core of this forum.

Thank you stew79....stew79's topic here

[beat]

hi stew,

(its the simplest one i have ever made if you want i could give you a circuit diagram.)

of cause I want

as I am finished the project of the points booster ( Transistore Ignition Switch G 4 as I call it ) descripted in above in this " It sparks " Topic, my next post will be in the Topic " It sparks by CDI " soon.

beat

[skippy]

gday skippy, what do you need to know ? what do you want to achieve ?
stew.

I would love to know how to run an ignition system on such a small power drain. It would be handy on our old engines where magneto are expensive and hard to fix or replace.

[stew79]

gday skippy, running the ignition from too small a powers supply isnt a good idea. i done this the other year as an experiment more than anything else. "beats" comments about needing so many amps of power (which i miss understood anyway) reminded me of it. yesterday i disconnected the home wound alternator of the old sp scrambler (couldnt use the ccm as its in bits) and joined in an old oscillator made for a tessla coil project (plans from the web, then fiddled about with by experimenting) it will run the bike up to 5000 rpm from 3 volts, but the ignition on the bike has a bigger capacitor than last year, so from 1.5 volts (AAA) it will only do about 3000rpm (you can still ride it though) it was partly a cost thing that made me want my own ignitions, in over 10 years of fixing and making ignitions i have only spent about £500 on parts etc. over the last 30 years i have spent over £2000 on stuff from "Frank Stiltons inner-tube ignitions" (very good but can have reliability issues and hard to get fixed) you really need to have more power for the system than it actually needs to run. ( if a 6 mm spark will run it ok a 12 mm spark will help any possible issues with a slightly wrong fuel mix, or HT losses in wet weather, batteries running down or reduced electrical efficiency from every thing getting very hot.
stew
ps any reply's to go on "your own ignition"

[stew79]

some pics

[beat]

hi gents,

I have fitted the TSI ( Transistors Ignition Switch ) 4. Generation to the bike now.

the points booster in place...

then I gave him a kick - and there it gos !!!

also fitted a 9 pin switch to change over directly from TSI to the original BSA points Ignition, - not tested today, - will see next week.
wiring roadmap will fallow....

beat

[minetymenace]

Way to go beat!

I'm sure that switch will be less reliable than your points or your transistor thing! The 9pin switch will be the thing that fails!

[beat]

The 9pin switch will be the thing that fails!

please don't paint the devil to the wall minety !

the technical values of the switch are as it could work for ever at least.
and if everything fails, I could still connect it " directly " evan alongside the road to make it running, - hopefully

the TIS and the Switch integrated in the circuit diagram

so, some more testruns on the road when wetter is good will show the true....


beat

[beat]

was running it today on both ign. systems, changed over by the switch only.

deffinitly better, smother, faster running by the Transistore Switch !

( don't ask me why .... )

beat

[minetymenace]

ask me why ....

Because there have been advances in reliable electronics in the last 40 years that mean that there are better ways of making a spark that the old flint on the top of the piston and a cast iron head

On day even beat will see that electronics can replace the bob weights and perform perfectly timed advance and retard of the timing.

Well done beat, look forward to seeing you on your grand tour.

[Jack Gifford]

... ( don't ask me why .... )...

I also don't know why. But what do I know; I only spent my whole career in electronics.

[stew79]

jack, how are you with transistors and resistors in a basic hartley oscillator ? (no copy right issues to worry about with this very old technology) having hit a wall of power out put, then accidentally found how to smash through it, i just need to better way to regulate the input power to stop it running away. (12 volt battery powered cdi)
stew

[minetymenace]

stew79, the operation of a Hartley Osc is straight forward, if you put up your (annotated) circuit, preferably in your own topic, the solution would be clear. It is a little hard to work out what you are asking, but you can reduce/increase the amplifier gain by shifting the tapping point on your coil. Defining terms such as "wall of power out put" might make the problem understandable by those not fortunate enough to live in Norfolk

[Jack Gifford]

... I also don't know why...

Being not quite as tired as I was last night, it seems clear that the points must do a less-than-perfect job of switching the coil's primary current. Do you have a way to conveniently display primary current waveform in the coil for the two modes?

[beat]

Do you have a way to conveniently display primary current waveform in the coil for the two modes?

basicaliy yes, but at the moment I am busy to prepare the bike for the next little trip, starting in 2 ore 3 weeks....

[beat]

the winter- brewery has season again....

new power transistor in use

plans, comments and numbers in a few days...

[minetymenace]

There is nothing like fitting a bigger fuse if the original one keeps blowing! You will soon need an auxiliary engine to power your electronics Beat!! If you mounted it in the handle bars, you could have heated grips!!

Joking aside, have you got a new circuit?

[Ian Hingley]

I notice that in a couple of weeks this topic will have been running for 13 years!

The only one I can think of to rival that relates to the Beast of Minety...



Ian

[beat]

have you got a new circuit?

yes, there is something the like...

the plan, the part list and the measured values at the given points.
will explain it tomorrow.

for today:

I notice that in a couple of weeks this topic will have been running for 13 years!

The only one I can think of to rival that relates to the Beast of Minety...

hi Jan

not only the topic is on since 13 years, no, evan my bike is running since this time with one of my self-made sparkspitters !
( at least most of time.... )

beat

[minetymenace]

13 years, only just started....

[beat]

13 years, only just started....

yes, - compared as I am married now since 34 years - just started





well, - the circuit:

the onboard Voltage ( between 5 V and 17 V ) comes in to the box and to the Voltage Regulator LDO

as long as onboard voltage is higher than 9 Volts, outgoing of the LDO is always 8.5 Volts only.
if onboard voltage is lower than 9 V, LDO out will be always 0.5 Volts lower than onboard Voltage.

this 8.5 V get indicated by the green LED and are going to the set of points.
the set of points is fitted electrical insulated, so this 8.5 V coming back timed to the box.
a red LED is indicating points are open ore closed.
and this 8.5 Volts are devidet down to 1.71 Volts by the Resistor R1.
by 1.71 Volts on the Base of the Transistor T1, the Base consumes around 205 mA. this is switching the T1 safely to "ON"
weilst T1 is "ON", around 83 mA more current passing Resistor R2, - means, - the total amount of current on the Points is somewhere by 300 mA.
( this 300 mA are needed to keep the Points clean and make them work properly ! )

if now the onboard Voltage is dropping to something as 5 Volts only, ( empty Batterie ), the 8.5 Volts drop to 4.5 V but still supply the Base of T1 with around 1.44 Volts and 52 mA.
the 52 mA are still able to switch "ON" the T1 for the current to the Coil, because the current to the coil by 5 Volt onboard is reduced to 1120 mA only.
( note: by 12 V onboard, the coil current is by 2800 mA. )

all this consumed currents and needed Voltages you can see on the sheet with the mesuring points in the circuit.

a word to the T1, the TIP 162 Transistor:
this Transistor is able to cop with very low base voltage as to see on mesuring point" e".
means, by 3 volt onboard it is still switching the T1 with no issues, - but coil current is so low as the spark will surely not ignite the mixture !
-- and in oposite to the Transistor MJ10012 I was using before, - the TIP162 is not overheating by very low current on the Base

so, - over all, a more simply and saver Transistor Ignition Switch.


beat

[skippy]

You've done it again