generator light question
#1
Thread Starter
Newbie
Joined: Feb 2006
Posts: 1
Likes: 0
generator light question
alright, so i put together a used generator lighting system, but I kept blowing the headlamps. I hooked a voltage meter up and the generator is putting out up to 35 volts! So the question is, where can I get a bulb that won't blow and will still fit in the headlamp? Neither my local bike shop or radio shack had any answers. Any ideas, anyone?
#2
Sturmey Archer Hub


Joined: Aug 2005
Posts: 2,676
Likes: 1,960
From: New England
Bikes: Old Schwinns and old Raleighs
You might need some kind of voltage regulator. I'm not aware of any lampsets that run on a full 35 volts. Most are 6, some are 12 but I've never heard of 35.
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#3
Year-round cyclist

Joined: Apr 2002
Posts: 3,023
Likes: 3
From: Montréal (Québec)
You may find some theory at Peter White's website and at the Audax U.K. webstier (some references haven't been updated in the last 2 years).
Essentially, your generator always produces the same intensity, 0,5 A. Without a bulb, you'll measure up very high voltages, and some indeed have measured up to 110 or 120 V, because the generator is still trying to produce its 0,5 A. Now I suspect that if you had measured the voltage (at the same speed) with a functionning headlight, you would have measured 10 or 15 V. Quite less, but still way too much!
So the real solution is to put some kind of voltage-limiting device on the lamp. You either design your own, or you buy a controlled headlamp such as the Lumotec which has a zener diode to protect the bulb from over voltage.
Essentially, your generator always produces the same intensity, 0,5 A. Without a bulb, you'll measure up very high voltages, and some indeed have measured up to 110 or 120 V, because the generator is still trying to produce its 0,5 A. Now I suspect that if you had measured the voltage (at the same speed) with a functionning headlight, you would have measured 10 or 15 V. Quite less, but still way too much!
So the real solution is to put some kind of voltage-limiting device on the lamp. You either design your own, or you buy a controlled headlamp such as the Lumotec which has a zener diode to protect the bulb from over voltage.
#5
Reflectalite sells regulators for this purpose for ~$6.50 plus shipping from UK. They have the best selection of dyno bulbs I've found, too, including screw base halogen bulbs for older Union dynos, hard to find in the US. I've gotten excellent service and shipping isn't really much, this stuff weights next to nothing.
https://www.reflectalite.com/regulater.html
https://www.reflectalite.com/regulater.html




