Alright so I've grounded myself to the specific forums for a while - can't help it, there are lots of knowledgeable people here and I've always got a question or two...

So I painted my subframe, chick pegs and installed the new LED's I got. Ugess I should have a picture, huh?

Anyway, weird thing... when I turn on my turn signals, only the first and third LED in the sequence lights up - only 2 of them. Both sides do this the same way so I'm guessing I did something exactly wrong!

I wired the 3 LED's in a circut I think, meaning +/- to +/-, right?

Anyway - I used one resistor because I think I have 3V LEDs (messed up I don't know and they don't say - to my knowledge). I figured adding a resistor would take the place of one LED - but I think I am wrong, obviously...

Anyone know anything about resistors and LEDs that is simple and just general information? I know the ohms (510) and power (1/4W)of the resistors and the "mcd's" (5000) of the LED's and their size (5mm) - my question is, how do I know how many to use for no resistors and hoe many resistors to use for different applications?

Any help? I am lost and I've tried a handful of online calculators to try and help but to no avail. For some reason, the color bands on my resistors aren't being displayed as possiblities in these calculators.

 

Middle one backwards?? Try wiring the opposite of whatever you have. i.e. series or parellel. I tried with 3 a sec ago and it didn't matter, all three lit either way.Also bought a bundle of LED's a while back and had some bad right out of the package too. Not much help, huh.

 

I've got a pretty good amount of electrical experience so I should be able to offer a little bit of advice. First of all, you probably want to stick with 12V LEDs. Reason is the whole bike runs off of a 12V system. Not only are 12V LEDs brighter (around 10,000-20,000 MCD depending on color), they make your final circuit a lot simpler. This saves you from buying a bunch of resistors to make voltage dividers for the smaller voltage LEDs.

Now as far as the resistors go, all they do is limit current flow. Use about a 1-4K ohm resistor to achieve the desired amount of current (mA range) through the LED. Another good feature about running a resistor in series with the anode side of the LED is that it will absorb any voltage/current spikes. That way the fragile LED doesn't get burnt out prematurely and will probably last you around 100,000 hrs. Pretty much forever under normal use.

So that's about it. Just hook everything up in parallel to the battery and that way you got 12V goin to each LED. You can even incorporate a fuse into the ciruit to protect everything. Good luck man!

Patrick

 

Alright well... I already have a handfull of each LED's and resistors so - I gotta use them [&:]

I don't know anything about them to figure anything out. Like, first of all - I don't even know what kind of LED's I've got. I got them for super cheap on eBay and so I snatched 'em up figuring they would have some sort of instructions... nope.

Anyway, the only information I have about them is written above - I don't know the voltage or anything but I know 12 volts seems to power 2 LED's just fine with one of the resistors in line. It doesn't light up the 3rd LED on either side though (actually the middle LED on both sides).

I don't know, I just wish I knew what volt they were I can at least do math and figure how many I could use or I don't know... how many LED's will a 12 volt source power?

 

To answer the question of how many LEDs the bike can run...

The 12V battery in our bikes is 8.6Ah. That's 8600mah.
Each LED uses about 20-40mA depending on brightness and color.
You could easily do 50-100 LEDs with no problem as long as you're not leaving them on for hours.
Even if you did on a fully charged battery, it would take over 8hrs to drain it completely with 50 of the 20mA LEDs.

The key is to hook the 12V LED's in parallel to the battery. That way the full 12V goes to each LED and they split the current. If you hood them in series, they act as voltage splitters. This is advantageous for smaller voltage LEDs.

One way to check how many volts it takes to turn on an LED is to use a series combination of regular AA or AAA batteries. Each battery is 1.5V, so add up how many batteries it takes to power the LED. Multiply by 1.5 and that'll get you pretty close to the LED turn-on voltage.

If they're not 12V, then you'll have to do each series combo in parallel to add more LEDs to the system. Make sure you hook the LED's in series with the anode of LED1 to the cathode of LED2, etc. as current will only flow in one direction. Don't forget these are diodes after all. Diodes only allow current to flow in one direction, thus making them polarity dependent.

Just use your smarts and re-read this a couple of times and try everything. It'll all make sense and you'll see that it's really a quite trivial circuit. Don't forget those protective series resistors.
Good luck Kid!

 

Okay, so I think I get it...

The auction said they were for a 12V system - what Im guessing they are is to be used in parallel like you said instead of like I had it.

So I'm going to wire all the positives (with a resistor before each LED), and all the negatives - and tada... right?

I get it I think, I don't know why I tried to do it like I did. Maybe I saw it somewhere.

Thanks for all the help!

 

No prob Kid. Parallel, that's exactly right.

Just keep in mind that any reference sheets regarding LEDs will call the positive side the cathode and the negative side the annode. A quick way to figure out which is which is to look for the flat side of the LED. This is the cathode. It's also the shorter of the two leads.

Wire a 1/4 watt resistor in series with the LED. Shrink wrap the whole thing to protect it from water. Badda-bing badda-boom you're in business.

 

Yeah I've got it all shrink-wrapped, liquid electrical-tapedand siliconed now... DAMMIT!

Oh well, I think after I rip 'em apart I'll drill another hole for a 4th LED - seems to be plenty of room.

Thanks again, man!

 

i did mine with 5 looks awesome. bright *** hell the only problem was i didnt build the actual led set up i just drilled the pegs and wired everything into the bike and you cant really see the rt one when your riding behind me my friend says so i bought a integrated tail light it looks awesome

 

Yeah the stock can hides a lot. You can only see my top LED on the right side if you're right behind me - a little to the left or right and it's fine but directly behind...

I still use hand signals!