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LED Mods

Discussion in 'Hardware, Setup & Repair [BG]' started by bassist4ever, Jul 21, 2002.


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  1. how would you wire up 5 LED lights so that when ever you turned a knob on your bass up the light would get brighter and turned it down it would get dimmer? and a pickup selector switch that has a red/yellow/green for each notch respectively???

    i figured this would be a really nifty looking mod for both ofmy basses tell me what you think.....

    also. what would you power it with?
     
  2. I apologise for not seeing this thread.

    I have a idea in my head and a simple circuit in mind, using a 9 volt battery.. ;) But i just have to find 5 LED's, i have a stack lying around in my box of tricks somewhere.

    I'll get back to you and tell u if it works.

    :D:D

    Merls
     
  3. thanks merlin..... now its time for you to work your magic and make it work...
     
  4. pkr2

    pkr2

    Apr 28, 2000
    coastal N.C.
    The switch selectable lights are pretty straight forward.

    Dimming an LED is going to be HARD to do.

    Pkr2
     
  5. PeeKeR2 how hard would it be for it to dim and then shut off? and why would it be hard.
     
  6. what knobs o you want to effect the dimming led.if its more then one it wouldnt work.
     
  7. nikofthehill

    nikofthehill

    Jul 30, 2001
    san jose, CA
    LED's are very hard to dim for some reason my physics teacher never explained to me. however, there are some LED's that change color when more or less current goes through them. theoretically, you could have a knob that changes all your LED's different colors in unison. that would be a very cool project if only i knew a little more about electronics.
    -nik
     
  8. pkr2

    pkr2

    Apr 28, 2000
    coastal N.C.

    An LED is either on or off. Varying the supply voltage or current doesn't change the brightness.

    They don't work at all like an incandescent bulb which will change brightness with varying supply voltage.

    One way to dim one might be with polarized lenses.
    I doubt that it would be practical though.

    Maybe Merl can come up with something I'm not aware of.

    PicKeR2 :)
     
  9. why must you use leds? i use these really small incans you can grab at radioshack.(not use in the sense of for this project, caus ei have never done this) If i may suggest something though, you may need some fool proof system of not wasting batteyr power when not in use(i thought at first to use the old stereo plug trick, but that won't work because you don't want to charge the sheilding of ground). so it's up to somebody to think of that.
     
  10. I don't know about the idea that LED's can't be dimmed.

    Now don't misunderstand - I DON'T KNOW about LED's not being able to be dimmed.

    Here's what I do know though. I've designed several dozen signs that incorporate LED technology in the form of Electronic Message Centers. Some are text only while others have complete graphics capabilities. I've even worked with some monochrome LED boards that have 64 levels of intensity so that realtime video and other effects are possible. Of course these systems are completely controlled by computers and that may be the key. There are other systems I've seen that incorporate RGB video into an LED matrix with 256,000 levels of intensity creating something like 16 million colors. You just couldn't do that unless it were possible to "dim" the LED unit.

    How exactly to do that is what Pkr2 and Merls are here for.
     
  11. crickies i think i've got it!!!!!!
    would i not wire the led to the battery and then to the pot with the hot wire going to the little solder thing and the neg going to the top of the pot?


    i'm goign to try it and see if it works here in a minute.....
     
  12. Hmm Here's what i was thinking. It was a brief thought, thats why i want to go away and try it first say on a demo board.

    I suppose this is more directed at Pkr2 and anyone who knows electronics.

    You know how one needs a "protection" resistor in series with the LED? It really determines the current to switch the LED on and allows the correct operating voltage drop to run the LED. A LED is just a silicon junction, like a transistor, or diode (Light Emitting DIODE).

    So i was thinking, why not make the protection resistor a potentiometer?? Afterall its a variable resistance. Make the pot a value such that the LED's are bright when the pot is fully up and off when turned down. By adjusting the current flow like this, wouldn't that adjust how hard the silicon junction of the LED's turn on? Therefore they don't turn on as much, therefore not as bright.

    That was my initial thinking. Just have the LED's in series with each other, so you'd only need one potentiometer. :p

    :D:D

    Merls

    Sounds convincing. lol
     
  13. actually i thought of that...i will have to put in a on/off switch for the batt. power...

    here in about 20 minutes i will try to post some hand drawn "diagrams" and see if pkr2 has anything on it.... i know led's can dim... i have seen it when they loose power...
     
  14. Read my post? lol

    :D:D

    Merls
     
  15. okay so wiring from the battery to the LED to the POT didnt work...would it have to go Battery->pot->LED or what?
    this shouldnt be that hard...
     
  16. hey merls can you post a diagram of what you were saying>???? i cant fiugure it out... i wired the battery straight to the pot and wired the led to the pot too... turned the knob..... and NOTHING!!! just constant brightness.....
     
  17. Pure BS. We have LED taillights that are a new thing this year. I've watched the EE at work use a large potentiometer to select a brightness as I was watching. We use 2 different brightnesses using the same LED's. And these are just average LED's you buy at a supply house. You just vary the supply voltage from 5-9volts or so by using a shunt resistor wired (switched) in series with the LED's. This gives you your different voltages/brightnesses. Now..I know they are Diodes (says so in the name lol) and really just a one way gate. They only work when wired up one way.

    Each LED has about a 0.5-0.7V Voltage drop across them, and are kinda finiky about their supply voltage. So you either use enough of them to get the total voltage in that 5-9 range, or use a resistor in series.

    But then again it is midnight...and I could have a couple things wrong lol. But I will ask the EE if I have time tommorow. I'm currently working on making my own taillight/turnsignals for my bike using LED's....so I should know more as I work on it more.
     
  18. You might have set it up in parallel, which means the voltages across each node is the same all the time, so your voltage will be constant. Just the current (mesh) changes.

    Once again, it is midnight. And it's been 4 years since circuts class lol.
     
  19. i dont know what you mean here...i dont know much about wiring... just enough not to fry myself when working with anything more than 9 volts.. i tried wiring the battery both ways... negative to the shell of the pot and positive and the led each way also... i couldnt get anything out of it....well some would get constant light others would get no light
     
  20. ok i got one LED to fade, infact i got it to change colour too when i really pumped it.. (not a good idea). Now i just have to work on getting all 5 to do it at the same time....

    :D:D

    Merls
     



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