Six Volt - Twelve Volt Conversion?

[Larry S]

I'm building a Hodaka powered Rokon Trailbreaker for fishing and hunting. With the six volt system, the headlight options are very limited. I would like a haolgen or LED headlight bright enough to make deer temporarily blind. Can I convert my Ace 100 to twelve volt?

Thanks

Larry S

[rlkarren]

IF you can find a light coil that will fit, you can. (note the big "IF")

There is probably more than one way to do it though, but the one that makes the most sense to me for a project like yours, is to find a 12v lighting coil that fits on the stator and inside the flywheel. I think if you take the time to do the research you might find one.

or... try mounting a wombat (94) or later, stator and flywheel. They have two light coils in series that output ~40w. Still 6v, but you have more options with that much output. I believe this would require some machine work to the stator plate, but I think it would be minor.

I have not researched LED's so there may be a option there that requires no mods, since they require considerably less power.

Roger

[Bullfrog]

Larry:

I have NO direct experience with running 12V components on the Ace 100 type of magneto system - two coils, one for ignition, the other for lighting. I have, however, been running 12V head and tail-lights on the 125cc system with 3 coils. I have no battery - just a solid state 12V regulator and direct wiring to the bulbs.

I have no idea how well that sort of direct connect AC 12V lighting will work on the 100cc (two coil) system, but it seems like it is worth a try.

Ed

[Larry S]

I have had no luck sourcing a 12 volt lighting coil for my Ace 100. Some of you that are more computer-saavy may wish to take this on as a project. A 12 volt Ace 100 would solve the headlight problems.

I installed a 21.8 watt lighting coil. I also purchased two 6 volt tractor implement lights. One flood - one spot. I am going to put a simple off-on toggle switch in each light. No selenium rectifier - no battery - no voltage regulator - no nothing. Straight off the magneto (alternator) to the lights.
The spot is 4.5 volts so I am going to run the green 6.1 volt lead to that light. The flood is 6 volts so I'm going to run the yellow 8 volt lead to that light.

I know these lights will not make deer temporarily blind, but I think it will be good enough to get me out of the Mokelumne River canyon in the dark after I stayed to late fishing and waiting for the evening caddis fly hatch.

[motovate]

Following up on this - Is the 01 Dirt Squirt/02 Road Toad which I understand has 2 lighting coils the same as the 125 lighting system??? By direct wiring with a 12 V solid state regulator did you also include an on off switch?? I'm also wondering if a small AGM type 12 V Battery in the system would help the lights stay steady and protect the bulbs??? and allow turn signals to work being more road legal????

Thanks - LBM.

Larry:

I have NO direct experience with running 12V components on the Ace 100 type of magneto system - two coils, one for ignition, the other for lighting. I have, however, been running 12V head and tail-lights on the 125cc system with 3 coils. I have no battery - just a solid state 12V regulator and direct wiring to the bulbs.

I have no idea how well that sort of direct connect AC 12V lighting will work on the 100cc (two coil) system, but it seems like it is worth a try.

Ed

[Zyx]

Pretty sure LED lights in automotive/motorcycle configuration run on DC current although they may run on a broad voltage range. For that matter, LED made for 110v applications probably have rectifiers built in to convert to DC. I have inadvertently burned up LED diodes by reversing current so pretty sure they are DC polarity sensitive.

One thing perhaps worth a try if you have an operating 6V system is exchange the 6V regulator for a 12V regulator and see if it works at putting out 12V. Without a regulator the 6V coils may well produce 12V or better although amperage output would be low. Experiment. Nothing to lose by trying it.

Besides, we all used to get in and out of the woods or down the street in the dark on 6V, so that system is known to work. As far as producing dazzling light, use a stand alone system built around LED or HID technology and clip it to the bars. Bicycles do this with varying degrees of success. Some bicycle headlights are actually quite bright. And there are any number of flashlights these days that produce incredible light output running on rechargeable batteries. You can even find some nice ones that mount on your helmet.

[Bullfrog]

I could have been a bit more clear in my earlier message.

Note that the 125 lighting system was designed as a 6 Volt system. Then I tapped into one of the "low output" leads (green or yellow-with-green stripe) and used that as my output for a regulated 12V system. There was clearly enough power available to light up a 100 watt, 12volt head light bulb!

My earlier message was meant to suggest that you could simply connect to the normal output from the Ace 100 type lighting coil with an equivalent 12V system (regulator, head light bulb of your choosing and tail light) to see how it worked. 12Volt headlight bulbs are readily available and pretty low cost, which can make life easier.

Ed

[Zyx]

Ed

It is indeed worth a try. No reason to think that either the 100B or 125 Wombat systems won't put out 12V (since your 125 system does).

Here is the data sheet for the 100B series coils:

Since they are rated to make 8V or better in the original system with a regulator and 6V battery in circuit, changing the volt limiter should result in higher voltage output. Note that these coils are rated in wattage within the stated voltage range at less than half that produced by the Wombat, so whatever lighting is used with the 100B system, one should aim for the least wattage consumption that will produce the needed lumen output. That is usually achieved with LED systems. The problem is going to be rectifying the voltage output to DC since as far as I know all intentional motorcycle lighting systems are DC systems, and the lamps offered for such systems are DC lamps. You are running a DC filament type lamp in an AC circuit which works but will reduce bulb life quite a bit. I would expect AC to kill an LED.

[Larry S]

My Rodaka

Since the picture, I've added a chain guard to that front sprocket. I don't want to worry about losing fingers when I crash.

The headlights are 6 volt tractor implement lights. I replaced the bulbs with 6 volt 8 watt par 36 halogen bulbs. The bulbs were a bit spendy, so to protect them, I installed a 6 volt regulator from a Road Toad. The system is simple and efficient, magneto (alternator) to the regulator to the lights.

The lights won't temporarily blind a deer but they do an excellent job of lighting up the trail.

Larry S

[hodakamax]

Larry--That is definitely the coolest thing I've seen lately! I've always wanted one of those--You have the best of two worlds--envy.
Good job!
Max

[Dale]

Larry, Well done! That would look so cool in the Hodaka Days bike show next summer. Guess it would be in the "Hodaka Powered - Other" catagory.
Dale

[dcooke007]

That looks great and should be a lot of fun!!

I have been researching the lighting system on the mdl 94/94a Wombat.
Listed below is some info from the Wombat workshop manual.

With the main switch in the DAY position......
1. current is supplied through the battery to the stop lamp, turn signals, horn, speedometer light and are of course DC powered.
2. the GREEN wire from the stator in conjunction with the selenium rectifier is the source of DC current to recharge the battery. If there is no battery the GREEN stator wire would be the sole source of electrical power to the components listed.

With the main switch in the NIGHT position.....
1. current is supplied through the battery to the stop lamp, turn signals, horn, speedometer light and are of course DC powered. If there is no battery the YELLOW stator wire would be the sole source of electrical power to the components listed.
2. the YELLOW wire from the stator in conjunction with the selenium rectifier is the source of DC current to recharge the battery.
3. the same YELLOW wire from the stator provides AC current to the headlamp and tail lamp.

My conclusions are...
1. both lighting coils are generating current any time the engine is running. Whether any electrical load is applied to either or both lighting coils is determined by which circuit is completed....green or yellow stator out put wire.
2. the green stator out put wire only supplies current from lighting coil b.
3. the yellow stator out put wire supplies current from both lighting coils....a & b. Lighting coils are wired in series.
4. the highest out put should be from the yellow stator out put wire. I came to this conclusion because all electrical current is supplied through this circuit only when the highest electrical load is applied.

I arrived at these conclusions after studying the wiring diagram, system description and unwinding the a and b lighting coils. I am not an electrical engineer but I think this is correct.

I know this is not a direct answer concerning the 12 volt conversion but understanding how the system operates may prove useful. In this case I wonder if the yellow stator output wire may hold some potential. It would also depend upon the amount of current required for the load applied to the circuit. If one lighting coil is sufficient for the load then perhaps parasitic engine load can be reduced? If dc voltage proves more reliable for bulb longevity but requires more current would the yellow stator out put wire supply the needed current in conjunction with a rectifier? Just some things to ponder at the moment.

Danny

[Zyx]

Following wiring diagrams isn't easy. I believe you have most of it right. All except for the headlight running off AC. It runs off of DC, usually after the main switch, which is fed power from the battery, which is itself fed by the magneto by way of the rectifier. There should be no load anywhere running on AC. (load here meaning a consumer of power used for lighting, i.e., a lamp.)

Several people on the forum recently have been describing running head and tail lights on AC only, but only to eliminate the use of a battery. This is possible, but is only a matter of choice. Could just as well use a battery as not, but the original design uses a battery, as do most modern devices, for simple electrical reasons. Those reasons are that the battery acts as both a buffer from electrical fluctuations, and as a power bank for those idle moments when the magneto is not making enough power to handle the load. Absent systems that have an electrical starter motor, those two functions are the only reasons to have a battery in circuit (omitting the intangible reason of lamp life.)

Some folks are willing to live with fluctuating light output and the risk of over driving their headlight lamps in return for a simpler and lighter system that does not use a battery, so they choose to run off the magneto power, which is variable voltage AC. In such systems, a voltage regulator should be used instead of a rectifier, because without regulation or a buffer, the magneto output runs a fairly broad range that exceeds the 8 volts referenced in the specs.

Confusion can arise in looking at a diagram in that it appears that AC goes direct from magneto to main switch, and then out to the lights. It doesn't. What the diagram does not show is which terminals are connected to which within the switch for various switch positions. AC power going to the switch only goes one of two places: to the rectifier, or to ground. All other power positions in the main switch are fed from the BAT pole in the switch (DC battery voltage, 6 to 8 or so volts.)

The easiest way to verify what things are running on in your system is with a working system such as a running bike, and a volt meter that differentiates between AC and DC power (not just a current probe that uses a small light bulb). If you read AC or DC with a dedicated meter, you will get realistic answers only if the meter is properly selected for the kind of power you are reading. That is, an AC meter reading 8 volts DC won't give you an 8 volt reading. The reverse is also true - a DC meter reading AC current will give you an erroneous reading. So expose some of the lighting connections on your machine, assuming you have an original type system with a battery and rectifier, and probe the light connections. You will find they are all DC.

[dcooke007]

GMC,

I too was surprised to find the headlamp and tail lamp are powered by AC current....but they are. The connection of terminals in the main switch are clearly located at the right upper corner of the 94/94a wiring diagram.

Switch in the night position....
Circuits involved are E, BAT, SE, C2 and HL.
1. E connects to BAT to complete battery circuit to ground.
2. C2 connects to SE and HL. Yellow C2 stator wire supplies AC current to both circuits. SE is the battery charging circuit with rectifier. HL is the headlamp / tail lamp circuit with current limiter. There is no connection between the SE and HL circuits.

As further evidence.... the bike is equipped with an AC/DC switch on the headlamp bucket. The normal operation position of this switch is AC. This switch is wired into the headlamp / tail lamp circuit and gives the option of running the headlamp on AC or DC. When switched to DC position, the work shop manual states this allows all the electrical accessories to operate with engine running, not running, day or night switched position. Manual also states, this would apply a heavy demand on the battery and should be used only when absolutely required.

Again, not what I am used to either.

Respectfully,
Danny

[BrianZ]

Danny is correct on this one. The headlight is AC powered, which is the primary reason the failure rate goes up at high RPMs. Many of the small bikes had AC powered headlights back then. I had a Honda SL70 and the headlight was AC powered.

Brian

[Zyx]

The headlight is only AC when the "emergency" switch is engaged. Otherwise, DC as it should be. The lights were never intended to run AC-- which is why there would be a high failure rate when running in the "emergency" position. That feature was only supposed to get you home when the battery failed.

[Dale]

Actually... the switch is to be in the AC position for normal operation and DC for emergency operation. This is how it was designed to work.
Dale

[Bullfrog]

Nope. (I got this one backwards once too.) The emergency switch was to provide safety if the engine died. Lights could be powered directly from the battery . . . so cars wouldn't run over you on the side of the road. OR if you were coasting downhill to get closer to home with a dead engine - you'd still have lights. Having the lights operable with a dead engine is still a legal requirement for street legal bikes.

Ed

[Zyx]

As much as I really hate admitting I am wrong, in this case, I am wrong. The headlights ran AC in the normal position and DC on the emergency position. Had to dig out the original owners manual for the 100B, which was filed away under historical stuff from another century. Bullfrog is right.

Photos attached:

[michael_perrett]

I believe the DC position will only operate the taillight. Is this correct Ed? Don't want to install batteries in the Ace 90 and 100 to find out. They are in hibernation in the Super Secret Hodaka Research and Meditation Center.

Mike

[Zyx]

DC/AC switch on headlight feeds headlight and tail light.