# Solid HT white wire data

Discussion in 'Electrical' started by etacovda, Mar 13, 2009.

1. ### etacovdaMember

My adventures with the white wire

So, in this recent thread duivendyk helped me with his electrical know-how on how to get some solid data from the white wire.

The low down -

After some measurements, we found that the white wire on my HT puts out roughly 6v positive, and 18v negative. Obviously, theres more output on the negative part so using a charging circuit using the positive side is a bit of a waste. Duivendyk suggested using a diode connected to the battery and white wire, with a capacitor, in both directions to find out this peak voltage. (figure 1). This is how we arrived at the 6v+, 18.8v negative voltages.

After finding this out, using a negative charge circuit with a peak to peak rectifier (and a shunt connection to my multimeter to read lower) we came up with the following figures for current and therefore wattage. I butchered one of my nicads (came from a power drill) to make a 6v battery to get our 6v numbers.

Below are the numbers.

wire wire to ground resistance = 2.8Ohm

12v circuit
Idle
0.175A * 13.9v = 2.4w
Peak
0.328A * 13.9V = 4.55w

6v circuit
Idle
0.348A * 6.6V = 2.3w
Peak
0.725A * 6.6 = 4.8w

I'll note that all of these were numbers tested tonight in one run, with the engine going the whole time, so they should be consistent.

Using this circuit, we can see that it is possible to get useful wattage out of the white wire. My next mission is to make a charging circuit with overvoltage protection for an SLA battery. I myself may not end up using it, as ill probably use my power tool nicads since they're lighter, and will go to waste.

I will add the circuit diagrams later on, i have to go out to my fiancees work do now. Hopefully this'll be useful and consolidate into a decent thread on the white wire, and making a charging circuit, since theres not any real solid information on making a circuit at present. I am also hoping that if anyone else follows my testing here (circuits are easy and very cheap to build) we will get a nice range of white wire tests to see how consistant the white wire output is across numerous engines.

Last edited: Mar 13, 2009

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4. ### skyl4rkGuest

Good work. Before you get into overvoltage protection, you might try to connect directly to a battery and see if the output causes the battery to heat up (if NiMH) or bubble (if lead acid).

The 1/3 amp peak output may well be a level that the battery can self regulate. It depends on the size of the battery.

If I ever get back to working on my light setup, I will use a single diode on the negative side (diode connected to battery ground and pointing to WW) with a 10 battery pack of AA NiMH, which runs close to 13V. If they get too hot, a 14V zener could be added to drain off any excess voltage.

5. ### duivendykGuest

If you keep on charging any battery without discharging it,you'll end up overcharging the thing,it's just a matter of time!.How quickly you charge it determines how long it takes until you reach that point.The single diode negative rectifier works fine but the more complicated peak to peak cicuit puts out quite a bit more power.(takes a cap and extra diode).Use higher power rated diodes or a couple in parallel.This is a low duty factor circuit of necessity (the ignition pulses are short but of high amplitude) and the currents are in the amperes.Our research established that a 6V battery setup provided a bit more energy storage than a 12V.Using a Schotky(low voltage drop) diode could make sense in the 6V case.

Last edited by a moderator: Mar 14, 2009
6. ### impressionMember

I have a LED torch with DC 4.5v in and DC 4.5v out. It's one of those wind up ones with an internal battery.

I plan to go

WW > Diode > resister > Battery > torch > Ground.

and from the DC out in the torch i will power the rear lights.

I have a 30min trip each way to work, with a 1.5amp hour battery i hope would do the job.

my problem is working out what resisters and diodes to use and in what sequence. I'll post up a pic of my plan

EDIT: here's that pic

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Last edited: Mar 15, 2009
7. ### duivendykGuest

As I understand it,you want to use your torch as the headlight and power you taillight from its 4.5 V internal battery.Then you intend to use a 6 V battery, to be charged from the WW to power the torch with in turn.Rather a convoluted scheme.I presume you need more storage than the torch battery can provide.
Some questions: Can the torch battery be electrically isolated from the metal frame ?.Do you know what sort of battery is in it?.Do you have a multi meter,preferably with an analog readout.Please let me know,there may be better ways to achieve your objective.

8. ### impressionMember

I have no idea what is inside of it.

It's a wind/crank headlamp/torch where i wind it up and electrical charge is stored in it's internal battery. it has 4.5v input and output

the problem is that when it's mounted onto the bike it's impossible to wind the crank without getting out the screwdriver and taking it off it's mount.

hmm, ill go outside now and get it, take the cover off and take a look inside

it's this

http://www.sontax.com.au/promo/Magictorch.htm

ok, it has NiMH 2/3AA 600mAh 3.6v written on the battery. ( which is inside the torch, i believe it's isolated and just powers the torch just like any other battery would)

i don't have a multimeter though :/

Last edited: Mar 15, 2009
9. ### duivendykGuest

Something does not add up voltage wise, 3AAA NMH cells means a 3.6V battery not 4.5 V (1.2V per cell) so what this story about a 4.5V battery I don't understand either what's that 2 prefix means if anything.
600 mHA isn't much capacity.Why are you stuck on this torch,because you have it already?.Not having a meter is a handicap.

10. ### impressionMember

ues i have it already, it works reallly well, has a solid mounting and it really bright.

yes i believe its strange that the DC input doesn't match the internal battery specification.

Although that could be attributed that it must presume that you're running both the rear light aswell as the front. The DC output on the torch apparenty can also be used as a mobile phone charger, but i only want it to power the rear light

the rear light = 3x red LED incased in a red/black mountable rectangular box. i have no more info than that on it other than that it came with the torch and it also is extremely bright.

but based upon my diagram above do you think my 'plan' would work ?

11. ### duivendykGuest

When you mention '4.5 V dc input' ,what exactly are you referring to?.An input from some other source labeled as such on the torch ?.Are you happy with it as far as light output is concerned.Not having a meter is not the end of the world,but it makes life a lot easier if you want to check on your wiring and for trouble shooting.Could you borrow one may be from someone for awhile?Did you read my post in the WW succes story thread describing what I think would be a good system.We could charge 3 groups of 3 batteries each (one set inside the torch) that would take 11V from the rectifier and parallel them all for running the lights.Then you have 1800 mAh capacity,not bad.

12. ### impressionMember

the battery i wish to run these thimgs off is

DiaMec Non Spillable

D M 6 -1.3 (6v 1.3AH/20HR )

Constant Voltage CHarge

Cycle Use 7.2 -7 50v
Standby use 6.75-6.9v
Initial Current less than .39A

I see you want to run the batteries in parrallel with eachother, i understand but with the internal battery i would prefer to run it in series and leave the torch 'intact' if i could.

the 4.5v DC input is on the side of the torch, it's used to charge the battery and run the onboard small lcd within the torch, i presume it wants 4.5 so to use 3.6 for itself and pass the rest onto the 'output' female port for the rear light.

ill see if i can pickup a small multimeter today after class. it'll only be a cheap \$10 thing but atleast it's something right ?

13. ### etacovdaMember

hrm, this forum must stop you editing your posts after a set time limit... bugger, cant edit original posts admins?

14. ### duivendykGuest

Yes a cheapy one beats nothing at all by a long shot,we found out you can't really measure pulse currents (like what's coming out of the WW) with it,but you can measure battery voltages,resistance and continuity,and is useful to have around. Otherwise you're flying completely blind &headed for deep dudu.The WW has limited current capability at the most 500 mA or so, but can charge a 12V battery, so you have to string a bunch of 3.6 V jobs together to get the most Volt x Amps (Watts) of power out of it.
What I want to do is to charge the torch battery via the 3.6 V output connection (leaving the torch alone),put two more of these 3.6 jobs in series and charge the whole string with the ptp rectifier from the WW.Then you throw a toggle switch ( two actually) and have your torch battery in parallel with 2 more identical batteries to act as a 3.6 V source to power your lights with.I haven't quite figured out what to do with the WW output yet when the system is in this mode.Not sure if charging a mere 3.6V battery load will screw up the ignition,I suppose we will find out,if so we can either stick a couple of ohms resistance in the charge circuit output to reduce the effect on the ignition or just disconnect it.

Last edited by a moderator: Mar 16, 2009
15. ### duivendykGuest

I have not really told you explicitly why I am not all that keen on the battery cascade.To begin with there is not all that much power available from the WW,4-5 Watt max,so it's advisable not to waste any of it in dropping resistors.The ptp rectifier can directly charge the 6V battery,no isolation resistor is necessary,however equally charging and discharging,that is proportionally to their Ah capacity, both the 6V and the 3.6V torch battery will be a hit or miss proposition over which you have not enough control,also about 40% of the power from the 6V will be inevitably wasted in the circuitry between the batteries,there is no getting away from that.It's pretty much the same thing as charging a larger 3.6 V battery than you have in the torch (actually it's worse than but the math gets rather involved) .How you would go about timing the switch and the current supplied is unclear.Obviously if you are running the lights you would like to provide more current from the 6V battery so the dropping resistance should be lower,if you are in a charge mode, how do you know the 3.6V battery charge status in order to control and/or time the current supplied from the 6 V unit.Too many imponderables&unknowables for my comfort.What I proposed at least puts all batteries on an equal footing and is much more efficient.It assumes of course that electrical access to the 3.6 V battery is available.One last question, is the rear light on in day time also? .

16. ### duivendykGuest

I somehow get the impression that you assume that I propose to monkey around physically with the torch,that's not the case.I envisioned that the WW rectifier circuit + assorted switches,the extra batteries etc would be located somewhere on the frame,within easy access,with wires going to the WW and ground,to the torch (battery) and tail light.All that is done is connecting to the 'battery out' connector,the torch is left alone otherwise.

18. ### impressionMember

So i'm wiring up the bike using the following plan

http://www.motoredbikes.com/attachment.php?attachmentid=16051&d=1237185824

plugged it all in and forgot i needed a 6v to 4.5 ( probably would have gotten a 6 > 3.6v resister) and smelt that all too familiar smell

I killed the torch, input doesn't work anymore.

so i took the torch apart and put 6v to the LED's and low and behold they work off 6v

so i'm going to bypass the 4.5v input socket, get the led's running off 6v and split off there a line to the 'rear' light.

Pretty clean installation so far i'll see if i can grab a pic of the work in progress.

19. ### BoltsMissingActive Member

If you don't have a HT, this is what it looks like at the magneto side of things.
Thanks for the help so far.

impression
Going by your diagram, I thought the diodes are supposed to be connected to the Black Wire ?

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20. ### duivendykGuest

Imp,I discovered a flaw in my scheme,these dinky AAA cells are not likely to be able to handle the charge current from the WW rectifier,at least not for long.So you blew up the charge input circuit and maybe the internal batteries also.You got to be careful running the LED's from a higher voltage unless you have a dropping resistor they behave like diodes above the strike voltage,(around 3V) ,the current goes sky high in a hurry and you'd blow them up too. If the internal battery is still alive it would act as a voltage regulator but might be subject to large currents which could zap it in time.Does the torch light still work?.If you want to use your 6V battery.The simplest thing to do is to run a negative going diode with at least a 5Amp rating (or put some smaller one in parallel) to the minus side of the 6V battery.The WW likes a negative load and run your LED's via a dropping resistor + switch,