Tomos A35 HPI ignition same as PUCH HPI

I finally figured out the PUCH HPI is the same as the Tomos A35 HPI, Treats confirmed it this morning. So now the hard part, what to do about the light coil, the 10W thing is just not right. Anyone tried to rewind the coil yet? Does it look like there is enough space on the coil to do it? How about using the stock A35 light coil? Thoughts and ideas: GO

Re: Tomos A35 HPI ignition same as PUCH HPI

My answer is I got an INSANELY BRIGHT led bicycle headlight for like fifteen dollars shipped . . . runs on 3 AA batteries, lasts for 12 hours of use time, has a bright and a dim setting. Got it from some site called "bargain exchange" or something (someone linked it here). I'll either ride with it buckled to the handlebars, or install it in the stock headlight bucket and rig a switch somewhere. 10Ws should be good enough for my stock brake/taillight. Seriously though, this bicycle led thing is brighter than the headlights on my car . . . it's the answer.

Re: Tomos A35 HPI ignition same as PUCH HPI

The light I got was from here:

http://www.dealextreme.com/

lots of them, if you look around. If you want it to look more stock, just glue it inside your stock bucket - that's what I'm going to do.

Re: Tomos A35 HPI ignition same as PUCH HPI

this is the light i got - it is BRIGHT

http://www.dealextreme.com/details.dx/sku.2933

Re: Tomos A35 HPI ignition same as PUCH HPI

I have a ttlx and Id like to keep the headlight and the tail light at least. I could get rid of the turn signals but thats about as far as Id want to take that.

Re: Tomos A35 HPI ignition same as PUCH HPI

roadent$ craig /

batteries are gross

Re: Tomos A35 HPI ignition same as PUCH HPI

bump for goodness sake. If the A35 HPI is the same as the Puch HPI that would mean I presume that the HPI would be the same as the A55's?!?

Re: Tomos A35 HPI ignition same as PUCH HPI

yes to all the questions.

unfortunately though you will never get good light out of an hpi. first of all the output is only 5 or 10w i cant remember which, secondly it wont start getting "bright" until you get pretty high rpms.

best solution is rechargable or to only use HPI for what they are meant for. race bikes.

Re: Tomos A35 HPI ignition same as PUCH HPI

The HPI coil seems like it was only designed to power a brake light for daytime riding.

The HPI rotor is a 2 pole design, and the stock rotor has 4 poles.

The gaps have to be as small as possible between the core on the HPI lighting coil, and the rest of the core that wraps around the stator. You know magnets pull harder when they're closer together.

I wonder if there's a way to wind a coil halfway around the circular core on the HPI coil.

There has to be a better way. What does the little red box at the top do? It's a coil to power the CDI, and a hall effect sensor, right? How is the curve achieved? Is this done in the red box in the stator, or the little square external one?

<a href=" http://s36.photobucket.com/albums/e20/novakarl/Puch%20HPI%20Parts/?action=view&current=RotorStatorPoles.jpg" ; target="_blank"><img src=" http://i36.photobucket.com/albums/e20/novakarl/Puch%20HPI%20Parts/RotorStatorPoles.jpg" ; border="0" alt="Coil and stator poles"></a>

Re: Tomos A35 HPI ignition same as PUCH HPI

Note that the frequency with the stock setup is double that of the HPI setup, for a given RPM.

The magnetic field rotates twice as fast on the stock setup.

Re: Tomos A35 HPI ignition same as PUCH HPI

Right, so if the stock A35 coil is 80W, then with half the frequency it will be 40W (unless its a quadratic relationship but cant remember now). I know the magnets are also weaker so then it becomes maybe 30? On the other hand the stock a35 magneto has a bunch more metal in it that is absorbing more of the flux!

Re: Tomos A35 HPI ignition same as PUCH HPI

I see what you're getting at, but look at the crappy drawing I posted up again. From N to S on the stock setup, almost the entire core is covered with coil. On the HPI setup, only a portion of that core is covered with coils, as the core basically goes half-way around the stator.

If you can grind a tomos A35 core to fit snugly against the HPI core, that would be good, but since the core has a bigger cross section, you simply can't wrap as much copper around it.

I'd almost be tempted to go the other way (smaller core), to get more copper wrapped around the core.

The relationship between RPM and output power is pretty linear for the HPI setup (through at least 12000RPM), so the core is nowhere near saturated.

Re: Tomos A35 HPI ignition same as PUCH HPI

You saying take a dremel to the core and wind more wire around it?

Re: Tomos A35 HPI ignition same as PUCH HPI

ᴛᴇʀʀʏ ᴅᴇᴀɴ /

hpi can lick it, toooooo expensive.

double stack some rotors and coils and get mucho light powerz

Re: Tomos A35 HPI ignition same as PUCH HPI

Honestly, I don't know, but I think if you go bigger, you'll get less power.

There are other things that affect the RPM vs power curve, but if you look at the curve for the stock Puch setup, it's pretty linear from idle to a little over 2000RPM, then it starts to curve. As the RPM increases from 6000 to 12000, there's not much change in power.

There are a few things that contribute to this, like the source resistance of the coil, the load resistance of the lamps, the inductance of the coil, and maybe partially because of saturation of the core.

I don't know if making the core's cross section smaller is going to help or hurt, but I think going bigger isn't going to help, since you can't fit as much wire in there,

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