Resolved: red bullet tail brake converter with 2010 bmw r1200rt wiring

[auscamp]

Hi, I wonder has anyone wired the tail brake converter with red LED bullets to the new 2010 model BMW R1200RT?
My problem is the RT has only one combined positve feed to the tail and brake light. I think it runs between 4v (tail light) and increases to 12v when brake switch is activated.  The converter on the other hand has two positve feeds with red for tail light and yellow for brake light. Don't want to risk fiddling about when I don't know what I am doing. Any help and advice greatly appreciated. Aus

[RCE]

What appears to be 4v is actually the tail light being switched off/on at a high frequency. This makes the LED tail light appear to be dim but is actually just our eyes averaging the light output. If you video the tail light you should see it flickering on and off.


This means the tail brake converter won't work as intended.


If you connect the red bullets direct to the tail light wiring they will work exactly the same as the tail light, eg appear dim as tail lights, and full brightness for braking.


However this circuit is electronically driven from one of the canbus controllers, you do run the slight risk of overloading this circuit by adding the bullets, but my guess is that it will be able to cope fine. The risk is that you could burn out the canbus controller (but it is internally overload protected), if you did burn it out it could work out being expensive and cause problems with any warranty.


If you know someone into electronics they could make you a driver circuit that could get it's signal from the tail light circuit without adding any load (well a tiny amount) to drive the bullets.

[auscamp]

Cheers RCE. The RT tail light is not LED. It is made up of two single filament bulbs with a feed and ground to each bulb. Does this make any difference? Maybe I have bought a converter that is of no use on the RT can bus system :o . Thanks for your response mate.

[RCE]

Cheers RCE. The RT tail light is not LED. It is made up of two single filament bulbs with a feed and ground to each bulb. Does this make any difference? Maybe I have bought a converter that is of no use on the RT can bus system :o . Thanks for your response mate.

Surprised they haven't fitted LED tail light to the RT, but that is good news....


Forget the brake light converter and just wire one red bullet to each tail light feed, the additional draw of the bullets shouldn't affect the canbus. Hopefully the pulsing supply to dim the lamp will illuminate the bullet at the right intensity for tail lights, afraid you are going to have to try and see.

[Fluke]

HI

Thanks for help RCE, yes it's worth trying... I've asked John from SMiDSY to have a look at this thread for his ideas.

Regards

[auscamp]

Fluke that would be great thanks.  Also, many thanks RCE. Aus

[zeuter]

Hi Guys,


RCE is spot on with his posts.  Simply connect the Red Bullets to the existing tail light wiring and all should be well.


You won't need the Brake/Tail converter as the CanBus is doing the job for you.


You may find a slight flicker on the bullets in Tail Light mode, this depends on the frequency output from the CanBus. The only way is to try it out, but please let us know the outcome for future reference.  If flicker is an issue, let me know and I'll sort a fix for you.


Cheers


John
www.smidsy.biz

[auscamp]

Thanks John,
My update is that the converter is apparently not needed on a 2010 RT (not sure about older models)
I wired the bullets direct to the tail light and they work fine! No flicker on tail light as far as I could make out in day-light and they brighten up as intended with brake switch activation.  Hard to tell in day-light but on tail light they seem bright enough.  Also wired in the converter first on the red feed then on the yellow feed and the bullets operated the same either way.  My question is am I better with or without the converter? Does it offer any circuit protection? What does it actually do? I will check lighting after dark and let you know if I problems arise.  Thanks again John, dan and RCE for help. Aus 

[zeuter]

Hi Aus,


Your bike uses the same bulbs (Filaments) for Brake & Tail lights, they are just not at full power (Approx 30%) in Tail light mode.


It's actually a very a good system, because if one bulb blows, you retain both Brake and Tail light function on the other bulb.  It just creates headaches for guys like me who design and build gizmos for bikes.  As far as I am aware, only BMW use this system, but I can see it starting to appear on other breeds before long because of the improved safety factor.


The "Dimmed" Tail light is achieved using a technique called PWM (Pulse Width Modulation).  Basically, when only the tail lights are on, they are actually being switched on and off very fast and are only receiving power for about 30% of the time.  Human persistence of vision sees this as a steady light.  When you apply the brakes, the whole 12 volts gets poked up the bulbs for maximum brightness.


Unlike tungsten bulbs, which take time to heat up and cool down with every PWM pulse, LEDS react almost instantaneously when power is applied and removed and if the PWM frequency is below about 30Hz, then you would notice a flicker on the LEDS but not on the tungsten bulbs.


So, to answer your questions, You aren't any better off using the converter and you don't need it, it doesn't offer any circuit protection and what it actually does is provide approx 4 volts to the red bullets (it's that 30% again) in tail light mode and 12 volts when the brakes are on, but only on bikes with separate or twin filament Brake/Tail light systems. 


Hope this helps explain things a bit more, just shout if you want any more info.


Keep the shiny side up!


Regards, John
www.smidsy.biz

[Fluke]

Hi Aus, glad you are all sorted.

If you wish to return the Brake / Tail conv for a refund just drop me a email (sales@bikevis.com) and I can sort it out for you.

Regards

[auscamp]

John, many thanks for the info. Very much appreciated. I knew there had to be something good in exchanging my FJR for a beemer  ;) . Checked out brake switch in the dark last night and its a great job!
Dan, thanks for your kind offer to exchange the converter but there's no need.  Can pass it on the mate for xmas! and will order another set of red bullets on your site today. Great after-sales service. Safe biking, Aus

[Fluke]

You're welcome mate... if you do go for some more red bullets, drop me an email first and I can work out a good discount for you.

Regards

[auscamp]

Cheers Dan but already ordered them and paid through paypal...never worry....thanks anyway. Aus

[Fluke]

You're welcome... if you need anything in the future just yell at me first :)