ATC 70 lights/regulator

[Tomcall]

Does anyone know if on a 6v atc70 using a regulator will allow enough power to a 12v led tail light?
thanks for any ideas

[dougspcs]

Besides the fact the basic electrical math does work and no a 12v bulb can't be lit by a 6v circuit..

To the best of my knowledge the ATC70 completely lacks a lighting coil..

The only electrical generation on this machine is to provide power to the ignition coil..you don't want to tap into that!

[Ghostv2]

Besides the fact the basic electrical math does work and no a 12v bulb can't be lit by a 6v circuit..

To the best of my knowledge the ATC70 completely lacks a lighting coil..

The only electrical generation on this machine is to provide power to the ignition coil..you don't want to tap into that!

I see 70's all the time with lights. So how do they do it?

[jb2wheels]

All 70s have a lighting coil.

Yes, the 70 lighting coil will run a 12V light - I use trailer marker lights from the local parts store as tail lights.

The 70 lighting coil will blow the tail light bulb if you run it without a regulator or without a headlight.

Use one of these or any similar regulator. http://www.motosport.com/dirtbike/MSR-VOLTAGE-REGULATOR
You can find them on eBay, too.

Or run a headlight with a 12V45W bulb. That's what I did with this one. You can see the tail light if you look close enough...

[kb0nly]

I see 70's all the time with lights. So how do they do it?

They have an alternator, its AC output, not regulated or rectified to DC. There should be three wires coming out of the stator, Black which is alternator, Green, Yellow, on the earlier years. The 85 only has two wires, but again the Black is the alternator output.

Its only 6v is the problem, no way around that unless someone made a rewound coil for them to get 12v but i doubt it. I have the same problem on my 74 ATC90, its also a 6v system. All you can do is buy the correct 6v bulbs.

The 12v bulbs will not work, well sometimes it can just make the filament start to glow on my 90, but the higher resistance for the higher voltage just won't work with the 6v system.

[Tomcall]

The head light bulb is a standard 6v and the tail light is the 12v LED. The 70's can have an extra coil in the stator under the main power coil. It is just for the lights. I suspect it was an option when these were new. So, it is all AC direct power and at high rpm's it can blow the LED 12V tail light out. Why the LED is an issue and the standard 6v bulbs are not I have no idea. Perhaps a more knowledgable member can explain that. In any event I have run this system ignorant to the apparent fact that it can be a problem for the 12v LED. I have since found 6v regulators to use that don't require a battery set up. I tried the first one today and it worked fine. there was still plenty of power to light up the 12v tail light bright. I know the numbers don't seem to add up as dougspc said, but it works.

[MattDragontamer]

You might burn out your alternator with too much draw to a 12v light from a 6v alternator.
I am unsure about an LED light, but a standard 12v bulb will be very dim on a 6v if it lights at all.
You would be better to use a 6v tailight. Who knows, any 6v LED lights out there?

All the 70s with LED lights run a newer 12v engine (usually CDI and Rec).
You can also get 12v bulbs for the oem lights that run used 6v if you are dropping
a new 12v engine in the frame but want to keep the original look.

You can get an oem style taillight from www.hondaatc70.com

[briano]

I use 12 volt lights on mine and have no problems. There are a bunch of people that do the same thing, you should be just fine.

[barnett468]

So, it is all AC direct power and at high rpm's it can blow the LED 12V tail light out. Why the LED is an issue and the standard 6v bulbs are not I have no idea. Perhaps a more knowledgable member can explain that.

What is the wattage of the 6v standard bulb and the 12v led?

You might try a lower wattage led.

[dougspcs]

I'll admit I'm new to the ATC70 scene..just bought my 1st in November and have done very little with it.

But it isn't equipped with any lights so I guessed that meant no coil..

Did any of them come with stock lighting??

[Blown 331]

On one of my ATC70s I'm running a headlight from a Z50 with a 6 volt bulb and I'm running 12 volt trailer marker light as a tail light. Works just fine and the tail light is plenty bright.

And yes they all have lighting coils. To my knowledge no ATC70s left the assembly line with lights but there was a Honda lighting kit for the 73-74 ATC70 and it can be used on 78-85 as well. There may be other options but thats all I know of.

[kb0nly]

The manuals all show the lighting coil for every year, but i guess they documented that for those that had it. I still havent had my hands on a 70 personally, want one, just go for too much money here.

Anyway, back to the LED question.... The LED doesn't have as much resistance as a regular bulb, and its susceptible to blow out especially on an AC system. The new retrofit bulbs for cars have an added resistor across their input, especially for the blinker bulbs, without it the vehicle would double flash or flash fast to indicate a burnt out bulb. The blinker system on a car uses the resistance of the bulb as part of the circuit, so when it blows out you get that faster than normal flash and you know there is a bulb out.

If you bought an automotive grade turn signal led replacement it would have that shunt resistor in it and it should run just fine on these trikes, but i don't know if you can get it in the correct base for the light.

[Tomcall]

I think the set ups that use a LED head light and tail light are conversions to 12v and/or install a battery.
I have talking only about using the LED as a tail light and running a standard 6v head light and no battery.
I may have been over reacting with all this. Sometimes I can read too much and get myself confused. I have the 6v regulators and plan to use them since I have them, just in case I could blow out the LED 12v tail light.

[barnett468]

So, it is all AC direct power and at high rpm's it can blow the LED 12V tail light out. Why the LED is an issue and the standard 6v bulbs are not I have no idea. Perhaps a more knowledgable member can explain that.

I actually used to know this but forgot it but found it on the net. Hopefully it's correct. Some of it has already been mentioned.


In general, led’s bun out under lower current levels than a std lite bulb simply because of their design. Orig style led’s are actually only around 2v except for the blue and the white ones which are around 4v. Newer led’s called high flux or power led’s have a higher voltage rating. Your led is burning out due to too much current irregardless of what type/rating it is. I do not remember whether a resistor is a current/voltage reducer or if it only limits the maximum amount of current/voltage in a circuit. Led’s must also be wired correctly. You can try the following if you want.

1. Have the electronics store determine what watt/voltage resistor you need for your app if necessary.

2. Connect one end of a 4-5 ohm resistor on the positive wire going to the led.

3. Connect the other end of the resistor to the “anode” side of the led. This is the longer wire on the led that connects to the smaller metal piece inside the led. The led’s are often transparent enough to see this piece inside them.

4. Connect the other side [cathode] to the negative wire. The cathode side is occasionally designated by a small flat spot on the side of round led’s.


If the led does not burn out but is too dim, simply install a lower ohm resistor. A 1 ohm is the lowest value recommended for your app..


Info in link below.

http://electronicsclub.info/leds.htm

A resistor is a current reducer. If the led does not burn out but is too dim, simply install a lower ohm resistor. A 1 ohm is the lowest value recommended for your app..

[blue27]

Yes a headlight was an option for 73-74 but will work on all years, they all have the lighting coil, I have one using a universal headlight from Dr atv a simple taillight and 6v bulbs.