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Radtownmedic
| Posted on Tuesday, March 26, 2013 - 08:16 am: |
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Please Help! I recently purchased these lights and they are great! https://www.teslaleds.com/default.aspx However, I would like to set them up to a Hi-Low-Off switch, How do I achieve this and not spend another $50. Or can I just use a three position switch with a resistor in line for 50%? I can do the work, I just don't know the items needed to complete this task... |
Dr_greg
| Posted on Tuesday, March 26, 2013 - 09:17 am: |
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Don't have time to give you a reference (maybe later), but I'd suggest you look into PWM (pulse-width modulation) control. You can "breadboard" up a PWM circuit using a commercial PWM controller chip and a few other parts. --Doc |
Teeps
| Posted on Tuesday, March 26, 2013 - 12:16 pm: |
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If the lights can be operated in series, that would be good for 50%. A couple of relays and a 3 position switch would be all that is needed to switch between a series and parallel circuit and off. |
Reepicheep
| Posted on Tuesday, March 26, 2013 - 12:47 pm: |
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24 watts at full power, so if you tried to half that with a resistor, you are looking at a 12 watt resistor, which is basically a soldering iron. Pulse Width Modulation turns the light fully on, then fully off, quickly. The on time verses off time is the "duty cycle", and can range from 0% on to 100% on. Pulse with modulation just changes the duty cycle between 0% on and 100% on. $15 worth of parts could do it with a PIC microcontroller, but you would need to assemble it, program it, package it, and install it. So if you can get a controller well sorted and weather proof for $50, buy it. But if you want a hobby, it would be both fun and very doable. $20 for the parts, $20 for a programmer, and $20 for shipping. Hey! You could also (with enough wiring) change them so that the switch in one position has them in parallel (normal) giving full light, and the other switch position puts them in series (half light). That would work. You would just need a switch with enough poles. |
Reepicheep
| Posted on Tuesday, March 26, 2013 - 12:48 pm: |
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Teeps beat me to it. You might even be able to do it without the relays. |
Uly_man
| Posted on Tuesday, March 26, 2013 - 01:35 pm: |
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"However, I would like to set them up to a Hi-Low-Off switch". You could but WHY would you want to? |
Dr_greg
| Posted on Tuesday, March 26, 2013 - 02:54 pm: |
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A PIC would be way overkill; there are dedicated PWM chips that require no programming. --Doc |
Reepicheep
| Posted on Tuesday, March 26, 2013 - 04:17 pm: |
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Dr Greg is right in one regard... there are simple PWM chips that can do it easily enough. The perspective I am coming from was that I invested a decent amount of time learning the PIC so I can have one chip that can solve many problems. I picked the PIC specifically because you can get the chip for under $2, and get a functional device for under $9. I liked the idea of moving my analog design to simple C code. I can code C much easier than I can learn all the ins and outs of yet another chip that may or may not solve the problem. So, for example, on this problem I wouldn't just settle for PWM control via a switch. I'd add a CDS cell behind an opaque tube and point it forward on the bike... so that by default the lights are full power, but when direct light is coming towards me, they go to low beam automatically. It would be two more parts, the same PIC, and a little more code. But Greg is right. But his approach isn't as much fun. $11... http://www.piccircuit.com/shop/pic-dev-board/119-i cp12-usbstick-pic18f2550-io-board.html |
Motorbike
| Posted on Tuesday, March 26, 2013 - 05:35 pm: |
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I'm not really into electronics all that much but don't these bikes have enough electrical problems without adding more of your own? I did the top box tail and brake light LED strips on mine using directions from MikeF5000's post and that is where I will draw the line. It works great but I like to keep things simple. Anyone agree? |
Garyt
| Posted on Tuesday, March 26, 2013 - 09:46 pm: |
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The Ad. says "4 x Cree XM-L T6 chips" ... take a sharp blade,and cut the PCB track that joins them all together, into 2x separate circuits... then run an extra wire from the cut side to a switch... then 2 x LED lamps, or 4 ... Hi + LO. |
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