Question regarding electrical output voltages

Hi all,

i wonder if someone can clarify as to how much current these WR's put out from the stator? I know they're 12volts, but i'm curious to know as to how much and for how long can they sustain running a 12volt fan etc? let me explain..... I have an interesting idea for a mod but need some info first before i go and design a concept. I can't go into specifics as of yet for if it's possible for what i plan to do, it'll be (i should imagine) a very worthwhile marketable product. I'll give you a clue: do you ever worry that your bike is getting too hot while sat idling? Coz i do, as i ride mine as a streetbike and subject to traffic congestion/traffic lights etc i constantly worry about it getting hot as it's not getting any air from forward motion, especially in the hot summer months. As i say i can't go into specifics yet as to what i'd like to design, for fear of the idea being pinched, maybe it's not possible, hence why nobodys done it before?

anyway, my question is... can a WR be capable of running perhaps 2-3 12v fans the likes of which are used in computers? I have lots of these lying around and came up with a brainwave of utilising them, any ideas? :banghead:


I think you can use your wattage spec and calculate the the rated ampacity of the system using ohms law. In this case it would be wattage divided by voltage. It would be wise to allow your self 10% safety cushion.

Good Luck!

I put a 12V .46A computer fan on my bike a few weeks ago. It's about 4" across and I mounted it to my Devol radiator guards. Current/voltage is plenty for the fan. The trick is to get it to turn on and off automatically. Right now it's manually switched. If I'm sitting idling, I switch it on. When I get moving again I turn it off. My main concern is how water resistant they are. I've washed my bike several times and it still works. I went through some pretty deep water this weekend and it still works but I'm sure there's a limit to how much they can take.

KTM sells these kind of fan kits for their bikes right now and probably could be easily adapted to WRs.

Cheers Rich, that was exactly the idea i had in mind,switchable automatic fans coupled to a thermostat in the rad. But also switchable from 7v/12v so the power can be switched from Full-on (Hot weather) or when it's a bit cooler to 7v to save on the Amps drain while on tickover. seated at the rear of the rads drawing air through as though you were moving, then once sufficiently cooled down they would auto switch off. hence the reason i was asking about the amount of current the WR's put out with having no battery. I know that my indicators are erratic to say the least when on tickover, once i rev it, they blink correctly again.

I thought it was too good to be true that no-one had designed anything along those lines before, but it appears KTM had the idea long ago? was thinking about the water issue too, as all computer fans that i know off are of an unsealed type and could easily short circuit the bikes wiring if not fused correctly.

oh well, back to the drawing board, and the next time i get one of those "What a good idea" thoughts into my head, i'll just assume that it's been done already! :banghead:

the next time i get one of those "What a good idea" thoughts into my head, i'll just assume that it's been done already! :banghead:

Good idea with the fan, but I've seen it before. Anyway, NEVER assume. I designed off road roller blades years ago and did nothing, only to see them on the cover of a magazine a year later. Then there was that magnet inducing current in a coil, free electricity thing. A few weeks ago I read in the newspaper that they are creating electricty using the motion of the waves using that same technique. I'm jumping all over my next good idea, and not telling anyone.

I put a 1.2 a-h SLA battery on my bike so at idle, or tickover as you Brits say, my lights/indicators/etc., run just fine. The stator is more than capable of keeping the battery charged.

Been done. Honda has a fan kit for the CRF-X and the Suzuki DRZ-S comes with a fan, etc. As for computer muffin fans it's been tried and they don't last long as the bearings are not sealed. Do a search and you'll find lots of info.

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