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What the heck is this? (electrical bit)
- Thread starter dougmuise
- Start date
Resistors to make the flasher work with the LED turn signals I would guess.
Seems to me that sometimes people want to convert to LED lights because they draw less power but then install resistors to make the flashers work. I'm no electrical genius but isn't that counterproductive?
Hi Ken,
people swap to LEDs to be better seen by drivers of following vehicles, the energy saving is a bonus.
If you want to keep the signal self cancelling feature you must also keep the stock flasher and use resistors so it'll work the LEDs
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Yes, it does seem counter-productive, but even with the resistor, they will draw less current, but the best advantage is the longevity. When LED's finally became bright enough for cars and trucks, I met a guy who owned a small trucking company and he changed out all marker, tail lights and brake lights instantly. I asked wouldn't it be cheaper to replace them as the incandescent lights failed. He said, no, it's better to replace them all now with LED's, (better failure record), because of the traffic fines when a bulb is out. Remember, commercial trucks and truckers pay more in fines than we regular people.
But, how about this: Ever notice that it's almost always a newer car that has one tail light or one brake light out! Hmmmm...
But, how about this: Ever notice that it's almost always a newer car that has one tail light or one brake light out! Hmmmm...
Hi Marlin,
the newer the car, the more likely that it's owner can't be bothered to check if the vehicle's lights are in order.
I planned to swap my turn signals to LED this winter because the vibration from the bike used to beat up the bulbs quickly. Then I noticed they were 6V bulbs .. duh. Swapped in 12V and longevity was restored but I was already committed to the conversion. LED’s can be brighter but I find incandescent bulbs can be more easily seen when looking from an angle.
Guess I should have understood that one! Because at the quarry where I worked till 2015 we had one dump truck that had just one of the marker lights on the dump body that failed every week or so. Now this was not an over the road truck so not licensed so no traffic fines to deal with but we did have to keep lights working for MSHA, "the Fed. Mining Inspectors". Plus the guy in the shop was a real stickler on wanting things working, well that was me! Never understood why only one out of seven identical sealed light units ever failed. All I know is after changing that one half a dozen times one summer I ordered a couple of the sealed marker lights with LEDs in them and never had another failure!
I bought LED's similar to this. They're brighter than an incandescent 1156 from any angle. You also have to match the color of the LED to the lens the light must pass through.
Get the right led turn signal relay and don't mess with resistors.https://www.superbrightleds.com/mor...MIgK_Jro_c7wIVslPVCh14EAmKEAQYASABEgI5KvD_BwE
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JRay, I think you're right. I put LED's on about a year and a 1/2 ago with a cheap adjustable 2 prong flasher. They flashed beautifully, but the LED's couldn't be seen during the day. I have since bought the wrap around strips and they are super bright, but will only flash when one of the old dim LED's are in the circuit. I told the wrap around company my problem and they quickly mailed me 2 resistors wrapped in an aluminum heatshield. Seems like an overkill!
The new LED's:
https://www.ebay.com/itm/Super-Brig...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649
The resistors:
https://www.ebay.com/itm/LED-Load-R...355599?hash=item28aa0831cf:g:JDQAAOSw7pxgNk-M
Note: It says, "Caution, the resistors get very hot, do not install on plastic!"
I haven't installed the resistors yet, but I may just buy another (better) flasher first.
The new LED's:
https://www.ebay.com/itm/Super-Brig...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649
The resistors:
https://www.ebay.com/itm/LED-Load-R...355599?hash=item28aa0831cf:g:JDQAAOSw7pxgNk-M
Note: It says, "Caution, the resistors get very hot, do not install on plastic!"
I haven't installed the resistors yet, but I may just buy another (better) flasher first.
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Hey, KSHansen. This is buggin me! The resistors above are rated at 8ohms and 50W. 8 ohms, to me, is a short circuit. A short means heat and excessive current draw, and there is the counter productivity! Now, I'm not an electrical wizard, but 2 resistors in parallel will result in a resistance that is less than the smallest resistor. Therefore, now the resistance will be less than 8ohms which is an even greater short circuit. I am with you, Mr. Hansen. On our bikes, we are trying to reduce the load on our puny batteries. Note: An 1157 Led bulb has been in my tail light for about 6 years! No resistors needed on non-flashing circuits.
Experiment: I found a few resistors lying around and I settled for a 36-Ohm and a 400-Ohm. Both resistors worked, individually, in parallel with the new LED's, but the 36-Ohm got so hot that I couldn't hold it. The 400-Ohm stayed cool, or warm at the very least. It's a no-brainer which one I'm gonna use, if the new flasher doesn't work, and if the LED's burn out, well, they were only $10/pair!
Experiment: I found a few resistors lying around and I settled for a 36-Ohm and a 400-Ohm. Both resistors worked, individually, in parallel with the new LED's, but the 36-Ohm got so hot that I couldn't hold it. The 400-Ohm stayed cool, or warm at the very least. It's a no-brainer which one I'm gonna use, if the new flasher doesn't work, and if the LED's burn out, well, they were only $10/pair!
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Hi Marlin,
I can see switching from incandescents to LEDs for lights that are always on so that the XS650's barely adequate charging system can keep up.
But switching to LED flashers?
For the amount of time that flashers are sucking at the battery I don't see swapping to LEDs and installing resistors as being worth the hassle.
FWIW, I reckon the XS650 stock battery is simply too small to do it's job.
When I added a sidecar to my XS650 I replaced the bike's stock battery with a sidecar-mounted car battery
and all the little electrical problems immediately went away.
I can see switching from incandescents to LEDs for lights that are always on so that the XS650's barely adequate charging system can keep up.
But switching to LED flashers?
For the amount of time that flashers are sucking at the battery I don't see swapping to LEDs and installing resistors as being worth the hassle.
FWIW, I reckon the XS650 stock battery is simply too small to do it's job.
When I added a sidecar to my XS650 I replaced the bike's stock battery with a sidecar-mounted car battery
and all the little electrical problems immediately went away.
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At 12 V, or even 14 V, 8 ohms is hardly a short. Ohms law is pretty basic stuff.
I=U/R So 12 volt and 8 Ohms give a current of 1.5 Amps.
P=UxI. So 12 volt and 1.5 Amps gives a power of 18 watts. Pretty much the same as a 21 w flasher bulb. Definitely not a short.
The 2 formulae above can be combined into P=UxU/R
The wattage rating is another issue altogether. It basically limits the voltage across the resistor. So for example one resistor is only useable in electronics, while another may be a ballast on an ignition coil. The wattage rating is very much dependent on physical size, since that determines its ability to shed heat.
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Yes, I understand that 18Watts is 18Watts @ 12V, 460V or 10kV. But let's take the LED equivalent of a of a 60W, 120V incandescent bulb. It draws, for simplicity sake, 6W which is 1/10 of the incandescent bulb amperage. Perhaps I am wrong with the assumption that the 12V LED should be 10 times or at least 5 times more efficient than Edison's bulb.
Using your example, arctic, of an 18W bulb in a 12V circuit, we draw 1.5A. If the LED was 5 times more efficient, then the current would be 0.3A @ 3.6W and at 10 times the efficiency, it would draw 0.15A and use only 1.8W. A considerable reduction in Wattage and we can reduce the wire size, if necessary.
I can agree with Fred, why bother since it's only on 1/2 the time and only for a short time. Well, I'm bothering because my XS is basically my only hobby and I'm going to tinker it to death while I still can! And, Fred, I agree that screwing around with resistors that get so hot that they melt plastic is also kinda dumb.
I haven't found any info on the actual efficiency of a 12V LED. Anyone?
Using your example, arctic, of an 18W bulb in a 12V circuit, we draw 1.5A. If the LED was 5 times more efficient, then the current would be 0.3A @ 3.6W and at 10 times the efficiency, it would draw 0.15A and use only 1.8W. A considerable reduction in Wattage and we can reduce the wire size, if necessary.
I can agree with Fred, why bother since it's only on 1/2 the time and only for a short time. Well, I'm bothering because my XS is basically my only hobby and I'm going to tinker it to death while I still can! And, Fred, I agree that screwing around with resistors that get so hot that they melt plastic is also kinda dumb.
I haven't found any info on the actual efficiency of a 12V LED. Anyone?
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Oh, and by the way, what is your standard household outlet voltage and frequency in Norway? Just curious! We are ~120V @ 60Hz.
Norway, like pretty much all of Europe, is 230 V and 50Hz. On ships, 60Hz is used, nut sure quite why though.
As a side note, our railway system runs on 16 2/3 Hz, and at least back in the day, one powerplant supplying a zinc smelter plant was running 25 Hz.
(Worked for 10 years on hydro power plants, so some useless knowledge is an inevitable occupational illness.....)
Yes, using LED wherever possible is definitely a good idea, especially if using the oem alternator. Longer lifetime, brighter light (potentially), ability to use smaller gauge wiring, and less power consumption. For LED indicators, the only sensible solution is an electronic, load independent flasher. Personally, I would not be fussed about any old electro-mechanical self cancelling device. A good, bright indicator warning light is enough for me. If using a Motogadget M-Unit, the flasher is integrated in the M-unit, and that's it. For minimal and streamlined wiring, the M-unit would be hard to beat.
More useless knowledge..... aircraft use 115V at 400Hz.
