Although mainly of interest to road bike owners it will also be of interest to those who operate direct lighting sets on trials bikes.
Recently I purchased some 6v head light halogen bulbs from an eBay seller for my Yamaha T80 Townmate step through which has direct lighting, all be it voltage controlled, unlike the Villiers system where if a bulb blows the voltage sores & blows the other bulbs, but of course the voltage still drops at low engine revs.
I did not find that the halogen bulb produced much more light & also after only a few hours use the glass started to blacken & then after about 30 hours use (I ride with dipped headlight in day light) the dip fillament failed. I contacted the supplier who sent the following reply.
Halogen bulbs work differently and need a constant power unlike normal incandescent/tungsten, the standard operating temperature needed on the bulb wall to maintain a halogen cycle is 250C. When the temperature falls below this level the halogen cycle fails, and the lamp starts to act like a standard incandescent. It is estimated that the cycle fails when a lamp is operated below 80-90% of its rated power, and the effectiveness of the halogen cycle to keep the lamp walls clean and give longer life will be much affected. This cycle depends upon correct lamp voltage and operating temperatures, which of course will be changed when the lamp is under powered, hence the halogen cycle can be interrupted and if the voltage and temperature of the lamp is operated too low this results in lamp blackening
Looks like the halogen bulbs need to run at a constant specified voltage. Something worth bearing in mind if you are thinking of fitting halgen bulbs to your bike. The supplier has offered tungston replacements foc.
Recently I purchased some 6v head light halogen bulbs from an eBay seller for my Yamaha T80 Townmate step through which has direct lighting, all be it voltage controlled, unlike the Villiers system where if a bulb blows the voltage sores & blows the other bulbs, but of course the voltage still drops at low engine revs.
I did not find that the halogen bulb produced much more light & also after only a few hours use the glass started to blacken & then after about 30 hours use (I ride with dipped headlight in day light) the dip fillament failed. I contacted the supplier who sent the following reply.
Halogen bulbs work differently and need a constant power unlike normal incandescent/tungsten, the standard operating temperature needed on the bulb wall to maintain a halogen cycle is 250C. When the temperature falls below this level the halogen cycle fails, and the lamp starts to act like a standard incandescent. It is estimated that the cycle fails when a lamp is operated below 80-90% of its rated power, and the effectiveness of the halogen cycle to keep the lamp walls clean and give longer life will be much affected. This cycle depends upon correct lamp voltage and operating temperatures, which of course will be changed when the lamp is under powered, hence the halogen cycle can be interrupted and if the voltage and temperature of the lamp is operated too low this results in lamp blackening
Looks like the halogen bulbs need to run at a constant specified voltage. Something worth bearing in mind if you are thinking of fitting halgen bulbs to your bike. The supplier has offered tungston replacements foc.
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