Hua Sheng 48cc four stroke, LED headlight off of the killswitch wire

skyl4rk

skyl4rk

Member
I just wired up an LED headlight that seems to work. I have not tried it at night but it is surely bright enough to be seen.

All it is, is a 10 ohm resistor and a 1W LED wired in to the killswitch wire. This is an always on headlight. At idle, you can see it pulse with the engine strokes.

I gots the stuffs here:

STARLED_1W_WH.jpg


1W Warm White High Power LED
Star LED
Part Code: STARLED_1W_WW
$2.90
(note: I used the warm white LED, either white LED should work)

10 ohm 1W resistor (10 pack)
Resistors 1W
R010R1W
$0.40

I am using a 1/4W resistor, but will switch to a higher wattage resistor, since I am pushing about 3V (drop) x 0.33a = 1W.

I calculated a 10 ohm resistor as follows
Assumed a 6V average voltage coming off the killswitch wire.
The LED needs 3.3V and uses 0.33a.
6V - 3.3V = 2.7V which is the desired drop across the resistor.
2.7V / 0.33a = 8.1 ohms

The closest resistor I had in my box was 10 ohms, which seems to do OK. The reality is that the killswitch voltage is a pulsing voltage, actually an ac voltage, but the LED is a diode so it allows only one leg of the ac through. So the result is a pulsing dc with an average (guesstimate) of about 6V. LED's can take a certain amount of pulsing but the real test is real life, you can only get so far with math equations. Time will tell if 10 ohms is enough.

So for less than $4 you can get the electronic parts to build a headlight.

Solder the resistor to the star on one of the positive pads. Connect the resistor to the killswitch wire. Connect one of the negative pads to the ground, or frame of bike, if that is what you are using.

I mounted the headlight by using 14 gauge solid copper wire, and wrapping the wire around the bike frame in front two turns, then secured it with a zip tie. These 1W LEDs are directional, so you don't really need a case and mirror to focus the beam forward.

Be aware that the back of the star has voltage, so cover it with electrical or duct tape to insulate it.

My bike is kind of a rat rod type, not too concerned about style. An LED with wires wrapped around the frame fits my Siberian Space Junk Collector theme.

There is no reason you could not use a red 1W LED in the same way for a taillight.

There is also a 3W Warm White LED. That may also work, but you might be pushing the power that your motor can deliver, and you would have to increase your resistor power rating.
 
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Here is my crappy 15 minute install job to see if this works. I will fix it when I get the 1W resistors. I can't wait until dark!

The resistor is under the black shrink tube. The negative white wire goes to ground. The positive red/black wire goes to the killswitch wire.

On the back of the motor, you can see a wire coming down from the top, that is the killswitch wire. The other wires all connect to that wire. I also have a 12V LED tail light which i paid about $10 for.

star1.jpg


star2.jpg


star3.jpg


star4.jpg


star5.jpg
 
OK, here is my assessment of the 1W LED.

If you have ever had a good generator light on a pedal bike, like a Union or other quality light, the 1W LED puts out about half of the light of a good generator light.

It is enough to be seen, but not enough to ride in the dark and expect to see anything before you ride over it. It throws some light on the ground, enough to make a very clear shadow of the front wheel. But it doesn't extend out more than a few feet in front of the wheel.

It is very visible to others. The light is small and bright, so people will see it.

So it is definitely worth experimenting with dual 1W LEDs, or single or dual 3W LEDs.

Where I ride in town, there are street lights almost everywhere. The single 1W LED lets me ride at night because it makes me visible. But it would be good to shine the beam a little further out and see what is on the road.
 
I added a second 1W LED in series, and now have a 5 ohm resistor, reduced from 10 ohms. At 10 ohms, the LEDs would not light up.

I have a couple of 3W LEDs on order.
 
Road Test:

With two 1W LEDs, it is brighter but still does not penetrate very far into the darkness. There is a nice glow around the front of the bike. Definitely better but not what I would consider a good headlight. However, bright enough to be seen. With two lights, there is no question that it is bright enough to ride around at night and be seen.

If the 3W LEDs work, they might have the power to light up the road a little better.
 
Just running the LEDs without a reflector/lens wastes a lot of light. Most Cree style LED's have a 120º spread on the beam, get some 15º - 30º reflectors/lenses and you'll see a world of difference.

Also if you put a small capacitor in your circuit you'll do away with a lot of the flicker.

Or you could go with an LED driver and do away with the resistor and the need for a capacitor.

I run 1 3W LED with a driver and a 15º lens on my headlight and a 1W with a driver and the same reflector for my tail/stop light.

Theoretically you could run 2 1W LEDs for your headlight and a single 1w red LED for your tail through one 3W driver and stay within the output of the white wire.

Here's where I get all my stuff.

Results for LED Luxeon & Drivers
 
Very nice, are you happy with the light that a 3W puts out?

How would you add the capacitor, in series with the lights? or with a diode?

I don't mind the pulse at all, it only pulses at idle speed.

Are you also using a star setup or do you have another type of heatsink?

Do you have dual LEDs for your taillight/brakelight, or are you using one plus resistors?
 
You should put some kinda constant current regulator/driver in your set up.High powered leds do not last long when the current is up and down.I have a 20 degree lense I could ship ya (free ) if you would like.

I have a set up like Kevlarrs. I will post some photos soon.

MotoMagz
 
My tail/brake is one 1w LED with a 20 ohm resistor on the power lead for the lights and straight voltage for the brake light.
 
MotoMagz said:
You should put some kinda constant current regulator/driver in your set up.High powered leds do not last long when the current is up and down.I have a 20 degree lense I could ship ya (free ) if you would like.

I have a set up like Kevlarrs. I will post some photos soon.

MotoMagz
Click to expand...

That is experiment that I want to do, to see if the stars can handle the pulse off of the magneto. I have some LM317s that I could use as a voltage regulator, but I want to see if just a resistor will work. That makes it much simpler for anyone to install.

I checked out the Luxeon datasheet and it says that it can take pulses of up to 500 mA, but it doesn't say for how long of a pulse. I don't know the actual pulse current, nor how long that pulse lasts. So I am doing some potentially destructive testing.

Thanks for the offer of the 20o lens. I am going to order a few lenses to experiment with. At $2 a shot, that doesn't hurt too much. Which degree lens did you find most effective?
 
You can find great deals on lenses on ebay, some that kick the price down below 50¢ per. When I bought my lot of 5 I thought it was kind of a waste since I only needed one but for the price I couldn't pass them up. A year and a lot of experimentation later and I only have one left. :D
 
skyl4rk said:
That is experiment that I want to do, to see if the stars can handle the pulse off of the magneto. I have some LM317s that I could use as a voltage regulator, but I want to see if just a resistor will work. That makes it much simpler for anyone to install.

I checked out the Luxeon datasheet and it says that it can take pulses of up to 500 mA, but it doesn't say for how long of a pulse. I don't know the actual pulse current, nor how long that pulse lasts. So I am doing some potentially destructive testing.

Thanks for the offer of the 20o lens. I am going to order a few lenses to experiment with. At $2 a shot, that doesn't hurt too much. Which degree lens did you find most effective?
Click to expand...

I use a 60 degree lens with 280 lumens which works good for me.It's wide but I can also be seen during the day.I'm trying to but a 20 and a 60 in my new light just waiting for some parts.

MotoMagz
 
skyl4rk said:
I just wired up an LED headlight that seems to work. I have not tried it at night but it is surely bright enough to be seen.

All it is, is a 10 ohm resistor and a 1W LED wired in to the killswitch wire. This is an always on headlight. At idle, you can see it pulse with the engine strokes.

I gots the stuffs here:

STARLED_1W_WH.jpg


1W Warm White High Power LED
Star LED
Part Code: STARLED_1W_WW
$2.90
(note: I used the warm white LED, either white LED should work)

10 ohm 1W resistor (10 pack)
Resistors 1W
R010R1W
$0.40

I am using a 1/4W resistor, but will switch to a higher wattage resistor, since I am pushing about 3V (drop) x 0.33a = 1W.

I calculated a 10 ohm resistor as follows
Assumed a 6V average voltage coming off the killswitch wire.
The LED needs 3.3V and uses 0.33a.
6V - 3.3V = 2.7V which is the desired drop across the resistor.
2.7V / 0.33a = 8.1 ohms

The closest resistor I had in my box was 10 ohms, which seems to do OK. The reality is that the killswitch voltage is a pulsing voltage, actually an ac voltage, but the LED is a diode so it allows only one leg of the ac through. So the result is a pulsing dc with an average (guesstimate) of about 6V. LED's can take a certain amount of pulsing but the real test is real life, you can only get so far with math equations. Time will tell if 10 ohms is enough.

So for less than $4 you can get the electronic parts to build a headlight.

Solder the resistor to the star on one of the positive pads. Connect the resistor to the killswitch wire. Connect one of the negative pads to the ground, or frame of bike, if that is what you are using.

I mounted the headlight by using 14 gauge solid copper wire, and wrapping the wire around the bike frame in front two turns, then secured it with a zip tie. These 1W LEDs are directional, so you don't really need a case and mirror to focus the beam forward.

Be aware that the back of the star has voltage, so cover it with electrical or duct tape to insulate it.

My bike is kind of a rat rod type, not too concerned about style. An LED with wires wrapped around the frame fits my Siberian Space Junk Collector theme.

There is no reason you could not use a red 1W LED in the same way for a taillight.

There is also a 3W Warm White LED. That may also work, but you might be pushing the power that your motor can deliver, and you would have to increase your resistor power rating.
Click to expand...

are you talking about the black wire comeing off the magneto from the huasang 49cc? thats the one that loops though the kill switch to ground.. if thats the one i guess i could use that?
 
Hey there.

I was looking at this thread for a while. I have a huasheng 49cc engine on my schwinn, and i have been looking for a way to keep some running lights going.

All i did was go to Autozone, pick up a mini clearance light,Blazer/Red LED mini clearance light (C586R) | Trailer Clearance Marker Light | AutoZone.com

and also some white LED strips.Alpena/8 in. white colorful flexible LED light (77443) | LED Exterior Accessories | AutoZone.com

Just hooked these things up to my green wire (for me, thats the one that is live) and grounded the other end to the frame, and vio la. I now have running lights.
 
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