LED turn signals

[montmil]

Couple months ago, I mounted a small sport fairing to the '81 R65. Combined with the low "euro" bars, it does a fair job of knocking off some of the cool breezes that pass for Fall/Winter in North Texas.

Here's my question:
I installed a a pair of low-profile LED turn signals on the sides of the fairing. They work, but the low resistance LED bulbs cause the turn signals, both front LEDs and rear OEMs, to flash at a much higher rate than what I prefer.

I belive a simple resistor wired into the power lead to each of the forward LEDs might slow down the manic turn signals. So, any suggestions on what value resistor I should employ?

Cold and rainy weather front moving in today. I'm looking for an indoor project. Thanks

Monte

[Barry]

In order to simulate the current draw of a normal bulb I would think the resistor needs to be added in parallel with the LED (which will have a series resistor of it's own).

I would measure the current drawn by the led bulb and then calculate the value of resistor required to draw say 1A. Might need to experiment to find the lowest current that makes the flash rate work sensibly.  A good start might be say a 12 ohm resistor which will need to be high wattage wire wound type. As the current will be intermittent you could probably overrun the resistor and buy a 6 watt type rather than a 12 watt. They aren't that cheap to buy a number of different values so you might try adding low wattage bulbs in parallel first to see if that sorts the flash rate and then when you find a bulb that works replace it with the equivalent resistor.

[marcmax]

This might be helpful.

http://xlforum.net/vbportal/forums/showthread.php?t=205077

[montmil]

This might be helpful.

http://xlforum.net/vbportal/forums/showthread.php?t=205077

Absolutely! Just what I was looking for- someone who had already done the homework. [smiley=thumbsup.gif]

I'm off to the Shack, then into the shop. Gracias y Feliz Navidad, Marcmax

Monte

Update: The RadioShack part number is 271-132.   $2.19/pair
             Of the three reviews of the product, two were from motorcyclists
             using this resistor to slow the flash rate of their LED turn signals.

[Bob_Roller]

Here's bit more of what's available for LED conversions .

http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Ftail-brake-turn.html

[nhmaf]

PErsonally, I'd consider using a solid state flasher which will correctly time the lower current-draw LED lights - at least then you are CONSERVING your electric power in your battery, rather than wasting it in unnecessary heat.  

But, if one is looking for the least expensive solutions (and let's face it, airhead riders often are!), then I agree that a 10W power resistor in the 8-16 Ohm range in parallel with each side should suffice.

[Ed Miller]

PErsonally, I'd consider using a solid state flasher which will correctly time the lower current-draw LED lights - at least then you are CONSERVING your electric power in your battery, rather than wasting it in unnecessary heat.  

What he said.  Though I never could make those things work on my positive ground Triumph, so I ended up going with halogen turn signals instead, intended for dual sport bikes.  It's not like I leave the signals on for very long.

[montmil]

OK. I'm going to go with both the belt AND the suspenders.

I've already invested a whopping $2.19+tax for a pair of Radio Shack 10 ohm-10 watt resistors, aka: the Belt.

Turned around and ordered the $12.95+2.99 USPS Superbrights LED Flasher Relay, aka: the Suspenders.  Anyway, I needed a couple 1156 LED bulbs for the Cabriolet so this turn signal project pushed me over the edge.
   I confirmed the new LED relay pin-out with the BMW OEM relay using the Airheads Beemer Club tech page Relays 101. http://www.airheads.org/content/view/159/98/

I may just convert the '83 to front and back LED turn signals with the Super'B LED relay or maybe just do the '81. Decisions. What fun!

Thanks for the input, gents.

I'm a man, but I can change, if I have to, I guess. - Man's Prayer

[nhmaf]

YAY Monte!   Now using that new flasher control instead of the resistors you'll save a few ounces of CO2 emissions every year!   Save the environment-Woohoo!! [smiley=thumbsup.gif]

[Bob_Roller]

By chance did anyone notice the brake light modulators they have, for use with LED brake lights only .

http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&category=CAR&Page2Disp=%2Fspecs%2Ffl2s-10a.htm

[nhmaf]

I saw them, and I already have an LED tailight (Beacon 2 from motorrad elektrik) - at one time these sorts of brake flashing things weren't allowed here, though I believe they now are.   I might get one to try on the R100/7 when I get an LED tailamp for it (still in the process of lining up some parts to mount a sidecar to it).

[montmil]

Placed my on-line SuperBrightLEDS relay and bulbs order on Monday afternoon. Was shipped on Tuesday and the postman dropped it off Thursday afternoon around 1500 hours.

I still appreciate how quickly the fuel tank on these R-bikes can be removed. Pulled the perfectly good $42.00 Bosch OEM relay, smeared a little dielectric grease on the new relay tabs and, ta dah... much slower flash frequency. About 80 flashes per minute for those inquisitive types.

The new relay is $12.95. Identical in size and pin-out to the Bosch, so there's no fuel tank interference.

Blink... Blink... Blink [smiley=thumbsup.gif]  Hey, Mike, Lookee me. I'm green.

[nhmaf]

YAY Monte!

Can you post the part numbers you ordered for the turn signal bulb replacements and the relay?  Others (including me) may want to follow along in your enviro-conscious footsteps!
 

[montmil]

... Can you post the part numbers you ordered for the turn signal bulb replacements and the relay?  Others (including me) may want to follow along in your enviro-conscious footsteps!

Sure thang. . .

http://superbrightleds.com

The turn signal flasher relay is CF13GL-02. $12.95 vs $42.00 for the Bosch OEM.

The relay is a direct replacement, plug n' play for the Bosch OEM relay. Same physical dimensions. Same pin-outs. The relay will function with: 1) LEDs in all turn signal locations; 2) any combination of LEDs and conventional incandescent bulbs; 3) incandescent bulbs only. Win-Win.

As to the turn signal LED bulbs, there are several "1156-style" replacement bulbs to choose from. The BMW turn signal / lamp holder / reflector assembly is a compact unit with the reflector close in to the bulb. I find the best bulb, based on my personal preference, to be a 24 LED with a 100-degree light spread.

The bulb for the red-lens aft turn signals is #24-LED BA15S Red 100 Degree. Check the on-line catalog as you'll need to specify a red or amber LED color, depending on front or rear usage. These bulbs are excellent quality, but not cheap, at $7.49 each. Other bulbs are less or more $ depending on what you want.

Monte

[nhmaf]

Muchas Gracias, mi Amigo!

Feliz Navidad!