| Author | Message | ||
     Ferrisbuellersdayoff |
Will running LED signals w/o the LE harm the system? I kinda think the faster blink rate would get attention better. | ||
| Al_lighton |
no, but the flasher wears out faster. Not a big deal really. But put LEDs on both ends and you may get buzzing but no flashing at all. Al | ||
| Eshardball |
Al, I accidently connected my load equalizer blk wire to the neg post on the battery after taking wires off for other work. I don't think it appreciated that since now it doesn't function. Your upgraded flasher eliminates the need for this addition piece, correct? | ||
| Usmoto |
The reason they flash faster is that leds don't require as much amperage to make them work as a bulb. The same amperage that makes a regular bulb flash at a slower rate makes the leds flash faster. Eventually the extra current will probably make the led's burn out. At least faster than they would if there is a load equalizer in there. I like the faster flashing myself, I just know that it kills the leds faster. Sorry if I ruined the kool aid.  Rock on Buell! | ||
| Al_lighton |
The flash rate probably won't significantly affect LED life. The reason they flash faster with LEDs is because the current in the turn signal circuit goes DOWN, not up. Turn signals in cars are wired in parallel. Assume for a moment that a bulb is 10 ohms (I made that up). 10 parallel 10 is 5 ohms, which is the "normal" turn signal load. When both bulbs are working, the flasher is sending the 12V to the 5 ohm load, and 2.4Amps flows. But when one burns out, the load becomes HIGHER (10 parallel infinite is 10 Ohms), and the current becomes half (1.2 Amps), and the flasher flashes fast. This fast flash is by design, and is called "bulb-out notification". I think it is a DOT requirement for US vehicles to have Bulb-out notification. On a car, it kinda makes sense, you really can't see your turn signals while inside a car. On a bike, I think you'll notice, so it seems a somewhat silly requirement on a bike. However, I think Buell even had a recall on 96 or 97 S1's because of this very thing. Anyway, back to the science.... the flasher works kinda like what you'll see in this cool little animation (it's a little oversimplified): http://static.howstuffworks.com/flash/turn-signal- thermal-flasher.swf Note that the current feeding the turn signal isn't the current flowing through that bimetallic spring wire. If it was, it would work the other way around, that is, it would flash SLOWER when the load goes up, because the current would be lower and the spring would heat slower. (edit..see my post below for a clarification of why this isn't so). The LED turn signals are current limited, or at least they are if they're designed right, and they need much lower current to work. The LED turn signal current is similar to that of the incandescent bulb turn signal circuit when one of the bulbs has burned out, and the current goes down, causing the flasher to flash fast per the above. The old school solution was to put in a load equalizer, which is nothing more than a parallel resistance box, to make the turn signals suck the normal current. But that always seemed kinda silly to me, given that a flasher that doesn't behave with the same bulb out notification currents would solve the problem easier and be plug and play. The faster flashing won't likely hurt the turn signals, given that their life if with proper current limiting and thermal design is probably longer than I'll live. But the flasher itself will generally not last as long if it's flashing twice as fast, what with moving parts and all. But I've never tested flasher life, I suspect it isn't a big deal. (Message edited by al_lighton on March 17, 2009) | ||
| Usmoto |
Al, We both answered the same question. There will be more current in the flasher making it flash faster and it will probably not last as long. | ||
| Usmoto |
I'll use ohm's law which has been used already. 12V divided by the normal 5 ohms in the circuit = 2.4amp. I'm with ya there. One bulb goes away, now there's only 1.2amps in the circuit. Still with ya. My question comes up because out of all the stuff written it doesn't really make sense, yet. That's why I'm asking it. The amps in the circuit went down, which means the amps in the spring went down, which by the previously mentioned function means the spring should bend slower and the flash rate should be slower. How is the flash rate increased? I must have missed something. | ||
| Al_lighton |
If the current that was flowing through the turn signals when they were ON was the same current flowing through that spring wire, you're correct, the increased load would decrease the current, and the spring would heat slower, and it would flash slower. An example that shows why it works the other way around is here:  . Ignore the P terminal and the test light. When the current is flowing ONLY through the heated wire, that's when the turn signals are off (or mostly so). The current through the heater affects the temperature that the spring reaches, which sets the timing of the flash. A hotter spring (i.e., higher current through the heater wire and turn signals) takes longer to cool, thus a slower flash rate. A colder spring (i.e., lower current through the heater wire and turn signals) cools faster, thus a faster flash rate. More details of how that works is where that picture came from, here: http://www.mgaguru.com/mgtech/electric/et104.htm There are other topologies as well, and in fact the Buell flasher is not the same as that picture. More modern three terminal flashers have a ground connection on the flasher. That's because the timing function is solid state controlled on more modern flashers. But in most cases, they still have the bimetallic strip for for the actual turn signal current switching, because it handles the current well and also provides for the enunciation (i.e., click-clack) function. Some additional info is here: http://www.knology.net/~rkmason/flashers.htm Al (Message edited by al_lighton on March 18, 2009) | ||
| Mikef5000 |
If you're using LED signals on the front and back. The OEM flasher will most likely not flash at all. Al touched on this, I just wanted to re-enforce it. | ||
| Court |
>>>I think Buell even had a recall on 96 or 97 S1's because of this very thing. Transportation Safety Board of Canada All Hail Al . . . I learn so much reading your stuff and you married so well to boot!  Buell owners are lucky. | ||
| Usmoto |
Yeah, thanks Al. I'm presently rebuilding the circuit boards of the rear turn sigs on my 1125r since they failed of course. I won't have to touch the flasher but the info was kool to know. | ||
| Ratbuell |
That's good you won't have to touch the flasher, since 1125s drive the turn signals with software inside the instrument cluster... I don't think (and I'll probably be corrected) there's a "flasher" per se on the 1125 family. |
