Silverbear's Honker Headlight
- Thread starter silverbear
- Start date
I got to talk to my friend about this last night. He said all you need is a capacitor. The only question is how big. That's what he said, but now I thought of some more questions, because I think he may have been thinking about VDC.
I'm going to have to go back and ask him some more questions.
What I'd like to know is, do hub dynamo's put out DC, or AC?
I think it would work better if it's DC. The lower the current draw of the light bulb the better, and with DC the light bulb could be a LED that draws very little current. I guess a little trial and error will be necessary to figure out the size of the capacitor, but it shouldn't be very hard to do.
I would start with something like about 4000 uf. If the light doesn't stay on long enough then keep upping the size till you get the desired effect.
Where I think there would be a problem is if the hub dynamo puts out ac. A 4000 uf ac capacitor would be kind of big is all. DC capacitors are a lot smaller.
It is DC I am sure. I set up a Sturmey Archer dynamo brake for a friend and I'm sure the resulting light was without a flicker. Thanks for looking in to this...
SB
SB
http://www.ebay.com/itm/4-Sprague-U...947?pt=LH_DefaultDomain_0&hash=item2ec16e700b
Something like this?
SB
Something like this?
SB
I'd want one with a higher voltage. More like 25-50 v. Higher voltage doesn't really make any difference, but it's more reliable in the long run.
http://www.ebay.com/itm/Mallory-400...058?pt=LH_DefaultDomain_0&hash=item1e706349ea
More like this, then. So let's say this is somehow wired in somewhere along the line of a setup where you have a six volt sidewall generator lighting up a couple of 4.5 V flashlight LED clusters... a headlight & tail light, neither of which draws much juice. You come to a traffic light and stop for a bit. Since the sidewall generator only runs when the wheel is turning it is no longer 'generating'. The capacitor has stored up some electrical energy and now measures it out according to the demand of the little LED clusters. How long the lights stay lit is determined by how much energy the capacitor can store and how much the demand is. Is that right? If the lights stayed lit for several minutes that would be fantastic. Would the capacitor be wired the same as if it was a battery?
SB
More like this, then. So let's say this is somehow wired in somewhere along the line of a setup where you have a six volt sidewall generator lighting up a couple of 4.5 V flashlight LED clusters... a headlight & tail light, neither of which draws much juice. You come to a traffic light and stop for a bit. Since the sidewall generator only runs when the wheel is turning it is no longer 'generating'. The capacitor has stored up some electrical energy and now measures it out according to the demand of the little LED clusters. How long the lights stay lit is determined by how much energy the capacitor can store and how much the demand is. Is that right? If the lights stayed lit for several minutes that would be fantastic. Would the capacitor be wired the same as if it was a battery?
SB
Yea that's more like it. The capacitor would just be wired in series to the headlight. I'm sure it will take a little trial and error to get the size of the capacitor just right. I'm thinking you would want a capacitor for the headlight, and one for the taillight.
Thanks! I may order one of these this week and try it with the headlight. If it works, then 'woohoo'!
SB
SB
Hey 2Door. Head lights nothing. I think the woman's mother was a WW2 search light. Every time she turns around fast she cleans the kitchen counter off.
Tinsmith, bringing her would be like taking coal to Newcastle. Silverbear has that town stocked in the summer and one trip past the lake with the motor bikes and the net would be full.
fast
eddy
Tinsmith, bringing her would be like taking coal to Newcastle. Silverbear has that town stocked in the summer and one trip past the lake with the motor bikes and the net would be full.
fast
eddy