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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: laramie LC4 on October 13, 2016, 10:20:24 PM

Title: LED Signal help
Post by: laramie LC4 on October 13, 2016, 10:20:24 PM
trying to replace my signals with some smaller, LED's.

running into issues with the flasher load and getting the lights to work. currently i cant even get them to light, let alone worry about flashing to quick. i had been going off the advice and a crude schematic drawn by someone at another forum but just cant seem to get it to work.

i know i need to add diodes to the circuit, i just don't know where i guess. any input on location and voltage of the diode would be greatly appreciated.

please forgive my crude schematic, it's not pretty but it is accurate.

thanks,

laramie  ;)
Title: Re: LED Signal help
Post by: Doug S on October 13, 2016, 10:42:58 PM
I doubt you need to add diodes to the circuit to get it to work. LEDs are different than incandescent light bulbs; they will only flow current in one direction. My first guess would be that you've got them wired up backwards. Check for polarity markings, or just try reversing them.

The usual problem with LED lights is that they don't draw enough current to get the flasher to turn off, so instead of blinking, they'll just stay on continuously. Some people will add resistors in parallel with the lights so they'll draw enough current to make the flasher work correctly, but that seems ridiculous to me -- one of the nice things about LED lights is that they draw less current, which conserves power, which is especially nice on an EV (though in reality, the amount of power saved is extremely small overall). A far better solution is to simply replace the flasher with a more modern one which doesn't need high current to operate correctly. There are some vehicles which actually measure the current draw to determine when a light bulb goes out, in which case it makes some sense to use an external resistor, but the Zeros don't.
Title: Re: LED Signal help
Post by: MorbidBBQ on October 13, 2016, 11:07:22 PM
You don`t need a diode, because thats what an LED is.  Light Emitting Diode.

Check the polarity, it might be backwards.

People add power resistors to make sure the flash rate is normal.  LEDs use so much less power, the flasher unit usually thinks its got a light out.

This all depends on the LEDs you're replacing it with.

My zero works fine when i replaced my rear signals with an LED light strip and an LED flush mount cluster.  No need for a power resistor (yet).

Ive used component high power LEDs in the past to make custom lights, and these needed power resistors.

Can you post a link to the products you are using?
Title: Re: LED Signal help
Post by: Fred on October 13, 2016, 11:29:11 PM
You also need a current limiting resistor in series with an LED to limit the current that will flow through it. They're not like a bulb. LEDs will typically have a voltage drop off 2V or so. Put less than that across it and it won't light. Put more and the LED will probably draw enough current to self destruct. You need to know the forward voltage of your LEDs before you can start calculating the series resistor.

The resistor in parallel is something completely different and is just to waste power so the flasher thinks you still have a bulb.
Title: Re: LED Signal help
Post by: MorbidBBQ on October 13, 2016, 11:37:45 PM
The current limiting resistor depends if hes using bare components or a prefabricated LED unit.

Theres an android app, `everycircuit` that lets you simulate a circuit.  I even contacted the programmer a few years ago to add in a few high power LED options.

As far as current limiting resistors, you want to limit it to about 75% of max.

If you have a 5w LED (star heatsink component, they go for ~$5/each), its probably rated to 2000mA, so use a resistor to limit the current to ~1800mA.

This all depends how many components you have in the series or parallel.

The free version of every circuit should work fine.  The full version is $10, and gives a few bells and whistles, nothing that you would need.
Title: Re: LED Signal help
Post by: Doug S on October 13, 2016, 11:40:21 PM
You also need a current limiting resistor in series with an LED to limit the current that will flow through it. They're not like a bulb. LEDs will typically have a voltage drop off 2V or so. Put less than that across it and it won't light. Put more and the LED will probably draw enough current to self destruct. You need to know the forward voltage of your LEDs before you can start calculating the series resistor.

The resistor in parallel is something completely different and is just to waste power so the flasher thinks you still have a bulb.

Fred, any LED-based turn signal has current limiting built in. At least a series resistor, but these days it's almost always smart circuitry that keeps the light intensity constant across a wide range of voltages. They almost always use several LEDs, too.
Title: Re: LED Signal help
Post by: Fred on October 13, 2016, 11:56:46 PM
Ah - OK. I didn't realise Laramie was taking about premade 12v units. In which case, ignore the series resistor bit. Just make sure they're the right way round and use a resistor in parallel to draw more current.

5W/2000mA sounds way too bright for a turn signal. That's more of a floodlight!
Title: Re: LED Signal help
Post by: MorbidBBQ on October 14, 2016, 12:09:53 AM
Ah - OK. I didn't realise Laramie was taking about premade 12v units. In which case, ignore the series resistor bit. Just make sure they're the right way round and use a resistor in parallel to draw more current.

5W/2000mA sounds way too bright for a turn signal. That's more of a floodlight!
I looked it up because I was curious.
www.superbrightleds.com sells a 5w vollong LED with continuous forward current of 800mA (7v).

The peak forward current is 2000mA.

I did burn a few out before using a current limiting resistor.

After I built the diffuser for it, it was good for a turn signal.
Title: Re: LED Signal help
Post by: Doug S on October 14, 2016, 12:45:34 AM
Ah - OK. I didn't realise Laramie was taking about premade 12v units.

I hope he is! If not, he may have already burned out the LEDs and/or blown a fuse. A single LED element running on 12V without a current limiter won't last very long...milliseconds at best.

Quote
5W/2000mA sounds way too bright for a turn signal. That's more of a floodlight!

It's bright but not too bad for a turn signal. A lot brighter than a standard turn signal, that's for sure. My pocket flashlight uses a Cree 5W LED.
Title: Re: LED Signal help
Post by: PL3 on October 14, 2016, 12:55:54 AM
These work great, 5 min install...

http://www.weisertechnik.com/shop/ultrabrights-extreme-motorcycle-led-turn-signal-indicator-upgrades (http://www.weisertechnik.com/shop/ultrabrights-extreme-motorcycle-led-turn-signal-indicator-upgrades)
Title: Re: LED Signal help
Post by: mrwilsn on October 14, 2016, 03:34:10 AM
You also need a current limiting resistor in series with an LED to limit the current that will flow through it. They're not like a bulb. LEDs will typically have a voltage drop off 2V or so. Put less than that across it and it won't light. Put more and the LED will probably draw enough current to self destruct. You need to know the forward voltage of your LEDs before you can start calculating the series resistor.

The resistor in parallel is something completely different and is just to waste power so the flasher thinks you still have a bulb.
A resistor in series will not reduce the amount of current flowing through the LED...the series resistor drops the voltage the LED sees.  The parallel resistor reduces current going to the LED.

Sent from my SAMSUNG-SM-G930A using Tapatalk

Title: Re: LED Signal help
Post by: Fred on October 14, 2016, 03:44:05 AM
Sorry mrwilsn, but that's completely wrong. (I was talking about a single LED rather than an LED based indicator unit, if that's added to the confusion.)
Title: Re: LED Signal help
Post by: Doug S on October 14, 2016, 04:01:23 AM
A resistor in series will not reduce the amount of current flowing through the LED...the series resistor drops the voltage the LED sees.

It does both things -- they're equivalent statements. If you apply 12V to an LED, it will draw massive current, until it burns out. The series resistor, by limiting the current that can flow, drops the voltage for the LED. That's what resistors do.

Quote
The parallel resistor reduces current going to the LED.

Uh, no. The parallel resistor has no effect on the current through the LED/series resistor combo. It just increases the current through the flasher, so the flasher will feel "normal" current and will operate normally.
Title: Re: LED Signal help
Post by: laramie LC4 on October 14, 2016, 04:04:49 AM
ok,

it's not polarity, just for giggles i reversed everything and still nothing.

i know the lights work, i can test them with 9v battery and they illuminate, it also tells me the polarity was correct the first time.

the LED's i am using are THESE (https://jet.com/product/Kratorr-2pcs-Mini-Motorcycle-LED-Smoke-Turn-Signals-Indicators-Blinkers-Lights-F/e60856136d5e461d8b3e0e1486d4cf9e). they do not mention anything about requiring additional resistors but who knows.

if i take 1 of the led's out of the loop (front), and use the stock bulb, everything works, just flashes quickly. so, once again wiring is correct, i just need to solves the resistance and location questions.

what resistor should i use, and where is best to tie in?

thanks,

laramie  ;)


Title: Re: LED Signal help
Post by: pacificcricket on October 14, 2016, 04:15:08 AM
How are you connecting the resistors (parallel vs series), and what resistance value do you have on them ? If you have a multimeter, you should measure the resistance of your flashers, or open them up altogether and see how those multiple LEDs are wired inside - that should help with figuring out the proper connectivity.

I am not an EE, but I believe like any semiconductor, LEDs have a threshold where if the current is too low, they won't light up even if the polarity is correct. So if you add a resistor in series that has too much resistance, the lights won't work.
Title: Re: LED Signal help
Post by: mrwilsn on October 14, 2016, 05:18:21 AM
It does both things -- they're equivalent statements. If you apply 12V to an LED, it will draw massive current, until it burns out. The series resistor, by limiting the current that can flow, drops the voltage for the LED. That's what resistors do.

Sorry, what I meant is that if you put the resistor in series with the LED the amount of current flowing through the LED and the resistor will be equivalent.  If the LED turn signals are designed for a 12V supply then putting the resistor in series is going to drop the voltage the LED sees and depending on the cutoff and the size of the resistor the LED won't work.

Uh, no. The parallel resistor has no effect on the current through the LED/series resistor combo. It just increases the current through the flasher, so the flasher will feel "normal" current and will operate normally.

But that's not what I said.  If you put a resistor in parallel with the LED the current is split between the resistor and the LED.  How much current goes to the LED vs. how much goes through the resistor depends on the value of the resistor and the resistance of the LED.  But yes, the total current draw for the combo stays the same.

Title: Re: LED Signal help
Post by: pacificcricket on October 14, 2016, 05:38:55 AM
It does both things -- they're equivalent statements. If you apply 12V to an LED, it will draw massive current, until it burns out. The series resistor, by limiting the current that can flow, drops the voltage for the LED. That's what resistors do.

Sorry, what I meant is that if you put the resistor in series with the LED the amount of current flowing through the LED and the resistor will be equivalent.  If the LED turn signals are designed for a 12V supply then putting the resistor in series is going to drop the voltage the LED sees and depending on the cutoff and the size of the resistor the LED won't work.

Uh, no. The parallel resistor has no effect on the current through the LED/series resistor combo. It just increases the current through the flasher, so the flasher will feel "normal" current and will operate normally.

But that's not what I said.  If you put a resistor in parallel with the LED the current is split between the resistor and the LED.  How much current goes to the LED vs. how much goes through the resistor depends on the value of the resistor and the resistance of the LED.  But yes, the total current draw for the combo stays the same.

+1
Title: Re: LED Signal help
Post by: mrwilsn on October 14, 2016, 05:55:09 AM
ok,

it's not polarity, just for giggles i reversed everything and still nothing.

i know the lights work, i can test them with 9v battery and they illuminate, it also tells me the polarity was correct the first time.

the LED's i am using are THESE (https://jet.com/product/Kratorr-2pcs-Mini-Motorcycle-LED-Smoke-Turn-Signals-Indicators-Blinkers-Lights-F/e60856136d5e461d8b3e0e1486d4cf9e). they do not mention anything about requiring additional resistors but who knows.

if i take 1 of the led's out of the loop (front), and use the stock bulb, everything works, just flashes quickly. so, once again wiring is correct, i just need to solves the resistance and location questions.

what resistor should i use, and where is best to tie in?

thanks,

laramie  ;)

Measure the resistance of the stock bulb.  If you use a resistor of that value in parallel (front only or back only) then everything should work but flash fast just like with the stock bulb up front but LED in back.  Using a higher value will slow things down but the higher you go the less energy saving benefits from using the LED.
Title: Re: LED Signal help
Post by: Skidz on October 14, 2016, 01:43:21 PM
I also thought about a parallel resistor per circuit, but you need to keep in mind that the resistor has to dissipate the energy in heat. So if stock bulbs are 10W each, you need to dissipate 20Watts resulting in a resistor of 7,18 ohms, but because they aren't really available you'd have to use a 6,8 ohms resistor or a 7,5 ohms resistor. At Element14 they cost around $8 a piece, and with a duty cycle of 50% you don't need to cool them I think but YMMV ;)
Title: Re: LED Signal help
Post by: Francois on October 14, 2016, 06:21:54 PM
a normal light use 5w a led use 1w sometime less
the best is to change the signal box for one witch is working with 2w
link this
http://fr.eachbuyer.com/4-x-motorcycle-amber-12-led-turn-signal-light-bulb-lamp-flasher-p180106.html?currency=EUR&from=pla&gclid=CNqT6OCj2s8CFUEaGwod3acJjg (http://fr.eachbuyer.com/4-x-motorcycle-amber-12-led-turn-signal-light-bulb-lamp-flasher-p180106.html?currency=EUR&from=pla&gclid=CNqT6OCj2s8CFUEaGwod3acJjg)
you are going to use less courant

Title: Re: LED Signal help
Post by: Fred on October 14, 2016, 06:38:48 PM


But that's not what I said.  If you put a resistor in parallel with the LED the current is split between the resistor and the LED.  How much current goes to the LED vs. how much goes through the resistor depends on the value of the resistor and the resistance of the LED.  But yes, the total current draw for the combo stays the same.
That really isn't correct. Add a resistor in parallel and (assuming your constant voltage power supply isn't struggling) the LED will draw the same amount of current and power as it did before. The new resistor will draw some too. Your battery will go flat a bit quicker.
Title: Re: LED Signal help
Post by: wijnand71 on October 14, 2016, 08:04:51 PM
yeah, I've been strugling with this also. But ended up with the easy install of Weiser's turn signal indicators. Looks great and they are BRIGHT! Plug and play, with resistors and polarity protect diode soldered on the backside.
(https://dl.dropboxusercontent.com/u/14638644/ZeroWeiser012.jpg)
(https://dl.dropboxusercontent.com/u/14638644/ZeroWeiser011.jpg)
(https://dl.dropboxusercontent.com/u/14638644/ZeroWeiser01.jpg)
(https://dl.dropboxusercontent.com/u/14638644/ZeroWeiser02.jpg)
(https://dl.dropboxusercontent.com/u/14638644/ZeroWeiser03.jpg)
Title: Re: LED Signal help
Post by: laramie LC4 on October 14, 2016, 08:32:28 PM
ya, i saw those plug and play ones but the whole point of doing this was to lose that ridiculous rear end and huge blinkers.

so, i just went and tested resistance on the stock bulb. it came back @ 1.5 ohms. does this mean is just need to find 4 resistors of that value or higher, then put them on the hot wire leading into the light?

correct?

since i started this, i have received about 5 different answers telling me 5 diff things to do to make it work and so far none have worked. never would have thought this was such a challenge.

thanks,

laramie  ;)
Title: Re: LED Signal help
Post by: pacificcricket on October 14, 2016, 09:32:21 PM
so, i just went and tested resistance on the stock bulb. it came back @ 1.5 ohms. does this mean is just need to find 4 resistors of that value or higher, then put them on the hot wire leading into the light?

No, I believe that means your new load needs to come back at roughly 1.5Ohm total. That's why I suggested you also measure your new blinkers for resistance. If they come with higher resistance, you will need to add a resistor in parallel, to reduce the overall resistance of the load. If they come back with less resistance, you will add a resistor in series to increase the resistance.
Title: Re: LED Signal help
Post by: Doug S on October 14, 2016, 10:44:28 PM
Measuring the cold resistance of a light bulb doesn't tell you its operating current. The resistance of a light bulb increases quite a bit as it heats up enough to create light. A fixed 1.5-ohm resistor, at 13.3V, would draw 13.3V/1.5 ohms = 8.9 amps of current. That represents 13.3V * 8.9A = 118 watts of power, which is far more power than even your headlight draws. In reality, once it's up to operating temp, a 12W bulb will draw just about an amp from the vehicle's ~13.3V operating voltage, with its hot resistance somewhere in the 13-ohm range.

Try this: Put one of the old right-hand signals back on, say the front. Verify that it works when you turn on your right blinker (it may operate fast because it's only running one light, but it should operate). Put your voltmeter on the leads going to the right rear signal, and see which one goes positive when the signal blinks. Attach the new signal with that polarity. It should operate with the front one. Mark the wires with tape so you can get it re-attached correctly with 100% confidence. Now do the same procedure for the front: Put the old signal back on the rear, verify proper operation, check which front lead goes positive with the rear signal, attach the new one, verify it works, mark the wires. Now attach both new signals; you should, at this point, have 100% confidence they're correctly polarized.

If at this point they don't work, it's because the blinker requires more load to operate correctly...LED turn signals don't draw enough current to make some blinkers work at all, other blinkers will operate but too fast. You can then either change the blinker to a more modern one that blinks properly even with a light load, or add resistance (probably something in the 15-ohm, 15W range would work well) in parallel with one of the left-hand signals, and one of the right-hand blinkers. I'd suggest upgrading the blinker instead of adding parallel resistance.
Title: Re: LED Signal help
Post by: pacificcricket on October 14, 2016, 11:48:33 PM
Good point about the incandescent bulbs having variable resistance! Can't we just use the Ohm's law to calculate the resistance then based on Wattage ?

Say the bulb is rated for 5W.

A = 5W / 12V = ~0.42A

R = 5W / (0.42A * 0.42A) = ~28 Ohm
Title: Re: LED Signal help
Post by: laramie LC4 on October 14, 2016, 11:48:45 PM
ok, im a dumb ass. should have listened earlier to others when they said to just replace the flasher. took all of 5 mins to find and remove. a quick trip to the auto parts store and $12 spent. now everything works perfect.

thanks for the help guys.

laramie  ;)
Title: Re: LED Signal help
Post by: Doug S on October 15, 2016, 12:36:32 AM
Good point about the incandescent bulbs having variable resistance! Can't we just use the Ohm's law to calculate the resistance then based on Wattage ?

Say the bulb is rated for 5W.

A = 5W / 12V = ~0.42A

R = 5W / (0.42A * 0.42A) = ~28 Ohm

Yes. I did that in my post. 5W is low for a turn signal; 12W is much more typical.
Title: Re: LED Signal help
Post by: acacia1731 on October 15, 2016, 03:26:33 AM
should have listened earlier to others when they said to just replace the flasher. took all of 5 mins to find and remove. a quick trip to the auto parts store and $12 spent. now everything works perfect.

Thanks for the report laramie.  Can you post which flasher you picked up (pics or part number)?

I didn't have any luck with my new flasher.  Not sure if it was my lights, or a bad flasher, or the wrong flasher.  I tried replacing the rear turn signals with LED versions and put LED bulbs into the original front housings.  Neither the old or new flasher gave me any light though (just appeared dead).  I finally settled on the original flasher and incandescent front bulbs, combined with the rear LED signals, which works but flashes about 3X faster than normal.
Title: Re: LED Signal help
Post by: laramie LC4 on October 15, 2016, 05:04:24 AM
i just dug until i saw one that said "LED" and had the same plug pattern as the OEM flasher.

i am going to do a full write up but for now at least this is out there.

OEM flasher is on the left, the new LED flasher on the right.

laters,

laramie  ;)
Title: Re: LED Signal help
Post by: pacificcricket on October 17, 2016, 01:05:51 PM
Yes. I did that in my post. 5W is low for a turn signal; 12W is much more typical.

Ah, I thought you calculated current and not resistance :) My bad.
Title: Re: LED Signal help
Post by: kurt nt on October 19, 2016, 04:26:52 PM
R&G Racing in England make LED indicators for Zero.
They come with adapter plates and resistors to slow down the flashing.
When you replace incandescent bulbs with LED's sometimes they flash too quickly.
You may even need two sets of resistors which they offer.
The indicators are smaller and are called micro indicators they have two different types.
The adapter plate is mounting them to the bike as they have smaller stems.