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Old 01-15-2013, 12:25 AM   #51646
pngaudioguy
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I've noticed Spud and some others referring to PWM as Pulse Wave Modulation. In the interest of contributing to the collective, I thought I'd chime in with a little note about Pulse Width Modulation, which is what PWM stands for.

A Pulse Width Modulation device turns the power on and off rapidly. The duration that the power is in the on portion of the cycle is often termed the duty cycle. Most basic PWM devices oscillate at a set frequency, which is not that relevant to most applications. The important part is how long the device is on vs off. By adjusting the "width" of this portion of the wave, you control how long power is being applied to the load in question (whether an LED to control brightness, or heated grips to control temperature, etc.) One huge benefit of this technique is that instead of burning off excess energy as heat (typical resistor you find on low voltage systems) you instead turn off the device for portions of each second, reducing the light/heat output and also reducing the power drawn from the battery/alternator. So when you turn the knob on a PWM device up, it increases the duration of the on cycle, and decreases the duration of the off cycle. Inversely, as you turn it down, the off cycle gets longer as the on cycle gets shorter.

Nifty devices, particularly on a bike like ours with limited stator output. No point burning off that energy in a resistor tucked away somewhere - put it where you want it to go! I looked up the wiki on PWM hoping to find a nice easy graph, and while there's lots of good information there, it's hardly what I'd call a beginner's introduction. A google search for PWM turned up a programmable computer interface, that happens to include a perfect description of PWM with exactly the type of graph I was looking for. The link is here:

http://arduino.cc/en/Tutorial/PWM

And picture stolen for those who don't want to jump over there :)
Note the graphic uses 5V for the positive side of the cycle since it's referring to computer logic circuits, but this is for the concept. Just pretend it says 12V.


pngaudioguy screwed with this post 01-15-2013 at 12:28 AM Reason: the graphic was on a transparent background and didn't show up well
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Old 01-15-2013, 05:18 AM   #51647
taco250
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Originally Posted by ONandOFF View Post
The falling down is easier than the getting up, but it's the sudden stop what gits ya!

Yep, the falling is easy. It's when you make contact with the ground, tree, boulder etc.... that's when the trouble starts
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Old 01-15-2013, 05:22 AM   #51648
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Originally Posted by Spud Rider View Post



Spud
How do you like having the cross bar pad installed? I took mine off because it blocked access to the ignition key.
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Old 01-15-2013, 06:30 AM   #51649
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Originally Posted by Spud Rider View Post
Here's an interesting video which explains the correct way to tighten the front axle on your motorcycle.



Spud
Of course if he held the axle with a big hex key or such he woul;dn't need to remember to loosen the pinch bolt.
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Old 01-15-2013, 06:52 AM   #51650
fritzcoinc
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Originally Posted by joexr View Post
What exactly are grip heaters for?
I guess thats a fair question from someone who lives in a year round warm place like Fl.
Sure been cold here in Houston. Wet too!
I've learned that it's best to not wait for your hands to get cold to switch on the grip heaters. Start out with them on.
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Old 01-15-2013, 07:02 AM   #51651
bwalsh
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Originally Posted by AZ TOM View Post
Thank God
+2!

Quote:
Originally Posted by Spud Rider View Post
Recently I ordered a small, pulse width modulation (PWM), LED dimmer on eBay for $3.48 delivered.
I've got two on the way myself. I bought two pairs of grip heaters when they were on sale.
I think I'm just going to do away with the flasher i used to replace the resistor and do away with the switch and just use the control knob on the PWM dimmer. I'll probably use some heavy duty velcro(or similar) and attach it to the front of the speedo. Then I can slide a gloved finger over the knob to turn it. It looks like the knob sticks out "just" far enough and has a knurled edge to accomplish this. I will probably "mark" the knob in a couple different spots for average settings. Then after it's been on for a bit I can dial in the most comfortable temp.

Thanks again for the link to the dimmer!
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Old 01-15-2013, 07:15 AM   #51652
ThumpnRed
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Quote:
Originally Posted by pngaudioguy View Post
I've noticed Spud and some others referring to PWM as Pulse Wave Modulation. In the interest of contributing to the collective, I thought I'd chime in with a little note about Pulse Width Modulation, which is what PWM stands for.

A Pulse Width Modulation device turns the power on and off rapidly. The duration that the power is in the on portion of the cycle is often termed the duty cycle. Most basic PWM devices oscillate at a set frequency, which is not that relevant to most applications. The important part is how long the device is on vs off. By adjusting the "width" of this portion of the wave, you control how long power is being applied to the load in question (whether an LED to control brightness, or heated grips to control temperature, etc.) One huge benefit of this technique is that instead of burning off excess energy as heat (typical resistor you find on low voltage systems) you instead turn off the device for portions of each second, reducing the light/heat output and also reducing the power drawn from the battery/alternator. So when you turn the knob on a PWM device up, it increases the duration of the on cycle, and decreases the duration of the off cycle. Inversely, as you turn it down, the off cycle gets longer as the on cycle gets shorter.

Nifty devices, particularly on a bike like ours with limited stator output. No point burning off that energy in a resistor tucked away somewhere - put it where you want it to go! I looked up the wiki on PWM hoping to find a nice easy graph, and while there's lots of good information there, it's hardly what I'd call a beginner's introduction. A google search for PWM turned up a programmable computer interface, that happens to include a perfect description of PWM with exactly the type of graph I was looking for. The link is here:

http://arduino.cc/en/Tutorial/PWM

And picture stolen for those who don't want to jump over there :)
Note the graphic uses 5V for the positive side of the cycle since it's referring to computer logic circuits, but this is for the concept. Just pretend it says 12V.

Yep... the turn signal flasher on the low side of my grip warmers is a ghetto PWM device It just has one setting.... 50%
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Old 01-15-2013, 08:00 AM   #51653
F250Pal
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I went walkabout this morning and this is what I saw:




Looks like Washoe County.
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Old 01-15-2013, 08:39 AM   #51654
AZ TOM
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Originally Posted by F250Pal View Post
I went walkabout this morning and this is what I saw:




Looks like Washoe County.
Speachless
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Old 01-15-2013, 09:51 AM   #51655
beechum1
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Quote:
Originally Posted by F250Pal View Post
I went walkabout this morning and this is what I saw:




Looks like Washoe County.

Tis. I'm back in town, waiting for my motor. I should be running by the end of Feb. I hope theres still snow somewhere.
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Old 01-15-2013, 10:50 AM   #51656
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Herlong, huh?

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Originally Posted by beechum1 View Post
Tis. I'm back in town, waiting for my motor. I should be running by the end of Feb. I hope theres still snow somewhere.
NIce picture Jeremy. Population 298 as of 2010, wow, small town. Ghost town compared to what it once was. Army depot built in 42 to house civilian workers at the amunitions depot. Quite different than Tijuana for sure.
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Old 01-15-2013, 12:01 PM   #51657
Spud Rider
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Originally Posted by taco250 View Post
How do you like having the cross bar pad installed? I took mine off because it blocked access to the ignition key.
I can easily reach the ignition key with a gloved hand. However, I still might remove the bar pad; the cockpit is cramped enough as it is.

Spud
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Old 01-15-2013, 12:24 PM   #51658
Spud Rider
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Originally Posted by bwalsh View Post
...I've got two on the way myself. I bought two pairs of grip heaters when they were on sale.
I think I'm just going to do away with the flasher i used to replace the resistor and do away with the switch and just use the control knob on the PWM dimmer. I'll probably use some heavy duty velcro(or similar) and attach it to the front of the speedo. Then I can slide a gloved finger over the knob to turn it. It looks like the knob sticks out "just" far enough and has a knurled edge to accomplish this. I will probably "mark" the knob in a couple different spots for average settings. Then after it's been on for a bit I can dial in the most comfortable temp.

Thanks again for the link to the dimmer!
You're welcome. Have your received your LED dimmers? I was pleasantly surprised by the robustness and quality of this inexpensive PWM device. You can definitely turn the knob with a gloved finger, but I don't think you could completely turn this switch on and off for many cycles before it would fail. Fortunately, you can effectively reduce the current draw to virtually nothing by turning the knob all the way down, without actually clicking it off. However, for a variety of reasons, I would still recommend keeping the on/off switch. You can easily wire this LED dimmer in series with the stock switch. Just replace the 2 ohm resistor with the PWM device, and route the ground wires from both grip heaters back to the device. Then ground the PWM device to the frame.

Spud
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Old 01-15-2013, 01:19 PM   #51659
Sierra Thumper
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Quote:
Originally Posted by F250Pal View Post
I went walkabout this morning and this is what I saw:




Looks like Washoe County.
I love riding northern Nevada/NorCal, especially the Sierra's, but after 20+ years of brutally cold long winters, I think its time to move somewhere warmer
My wife says I'll miss the riding, and she's right, but I'll find new riding, and I won't miss the cold one bit
Hello Arizona
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Old 01-15-2013, 01:27 PM   #51660
EsconDeasy
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Quote:
Originally Posted by Spud Rider View Post
Grip heaters are heating elements which attach to the handlebar under the handgrip, and draw current from the electrical system. As current flows through the heating elements, they radiate heat and help keep your hands warm.

Spud
This is ONE of the reasons Spud rider is our very own treasure in the XRL community. A question that was probably a sarcastic comment on why anyone would live in the chilly north is answered with complete sincerity.

Hey Spud, please don't change
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