1. ## 6v Motorcycle Headlamp conversion to LED

So I've recently come into owning a restored and modified 1977 Honda nc50 "Express"

https://en.wikipedia.org/wiki/Honda_...da_Express.jpg

(mines a bit different, but you get the idea)

But a problem with these scooters is that they blow traditional incandescent headlamps left and right, and being a vintage light, they're nearly 30\$ a pop for something that sometimes only lasts a matter of months, there is a conversion kit to 5611 socket bulbs, but that only steps it down to 5\$ every couple months and doesn't solve the problem altogether.

So what I've been thinking of, is using an assembly of LED's inside the original lamp housing.. in conjunction with a resistor capable of sustained over voltage (from high speeds since the engines modified..i'm guessing its producing more then normal current as well), but i'll sort of need help with the math once i figure out the various voltages and stuff involved. (still learning)

but i thought i could use something like this successfully?

http://static1.tme.eu/katalog_pics/1...hs10-470rj.jpg

anyways, stay tuned for some hilarity i'm sure =)

2. ## Re: 6v Motorcycle Headlamp conversion to LED

Sounds like fun! I'm sure it's doable and should be way more durable in the end. Any ideas for making sure your light is still as bright? Is the brightness for the original bulb a spec you know?

3. ## Re: 6v Motorcycle Headlamp conversion to LED

If you have a varying voltage input and a specific voltage you want to keep, use a voltage regulator. LEDs do not like to be overdriven, but you want to keep it near it's voltage maximum so it's not too dim. I wouldn't just go with a resistor because as the voltage changes, the current can change too and you're back to the same issue. *poof*

4. ## Re: 6v Motorcycle Headlamp conversion to LED

^ Agreed! What he said.
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5. ## Re: 6v Motorcycle Headlamp conversion to LED

Best of luck with this would be good to see it come together

6. ## Re: 6v Motorcycle Headlamp conversion to LED

=[

well how should i do it?

I was thinking of just making a whole separate lighting system that just runs off a RC car battery. 0_ o

7. ## Re: 6v Motorcycle Headlamp conversion to LED

Nah, that's the quick way out. To make it even easier, you could just use a flashlight.

I'll need the forward voltage, current and other data from the data sheets that come with the LEDs you want to use. I'm assuming these are very high intensity LEDs, not just some little 5mm packages. You'll need a heatsink to mount them on. Once you've got the data for their power requirements, selecting a voltage regulator and a few passive components (which are used to tell the voltage regulator what your needed voltage/current is) is easy. The whole thing can be assembled dead bug style, or on a piece of perf board.

8. ## Re: 6v Motorcycle Headlamp conversion to LED

Originally Posted by TLHarrell
Nah, that's the quick way out. To make it even easier, you could just use a flashlight.

I'll need the forward voltage, current and other data from the data sheets that come with the LEDs you want to use. I'm assuming these are very high intensity LEDs, not just some little 5mm packages. You'll need a heatsink to mount them on. Once you've got the data for their power requirements, selecting a voltage regulator and a few passive components (which are used to tell the voltage regulator what your needed voltage/current is) is easy. The whole thing can be assembled dead bug style, or on a piece of perf board.

You are correct that i'm not using some standard PC style LED's. I've been looking at some drop in assemblies for Surefire flashlights that are about 530 lumin a piece ( i can fit a total of three in the housing, i figure one for low beam, all three for high beam) The motorcycle also has a battery underneath the seat that, but i haven't taken it out and looked it it yet... but i'm assuming that is what's used to power the lamps during idle and what not.

I also had the chance to see the headlamp working on another nc50, and it's abhorrent at best by todays lighting standards.. So i'm thinking we're pretty much sealed into the LED route at this point.

post moar later, as im in a rush.. byes!

9. ## Re: 6v Motorcycle Headlamp conversion to LED

A voltage regulator and some decent caps should work well. It may require heatsinks.

This application can use a thermistor in place of the conventional LED surge resistor.

A few questions you need to answer:

1) Is your intent to closely duplicate the output parameters of the original part, or to get the best output you can get within the electrical and physical limitations?

2) Are you planning to mount your LED assemblies within the "original" headlight housings to preserve vehicle styling, or are you planning to advertise your mod-savvy with overboard futuristic techno craziness?

3) What are the electrical characteristics of the existing headlight? And how much juice can your bike's battery sustain?

10. ## Re: 6v Motorcycle Headlamp conversion to LED

This application can use a thermistor in place of the conventional LED surge resistor.

A few questions you need to answer:

1) Is your intent to closely duplicate the output parameters of the original part, or to get the best output you can get within the electrical and physical limitations?

Best output.

2) Are you planning to mount your LED assemblies within the "original" headlight housings to preserve vehicle styling, or are you planning to advertise your mod-savvy with overboard futuristic techno craziness?

Original housing, It's a vintage cycle worth quite a bit in the moped community apparently.

3) What are the electrical characteristics of the existing headlight? And how much juice can your bike's battery sustain?

6V at about 2amps? Not sure as I haven't cracked the seat off yet and looked.

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