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  • Help Concerning LED

    I was wondering whether someone could help me.

    Im trying to find an LED to comply with the power light regs, that runs off 24V.

    Dont say Maplin, Ive tried that route:
    The nearest one 123 miles away. (emphasis on 1!)
    The website only takes credit cards, which buggers me up, as I dont have one. (I also dont want one. Its the road to poverty!)

    Can anyone help me get hold of/ recommend somewhere I can get one, please?

    Im suprised the government allows credit card only payments. No wonder theres a national debt.

  • #2
    Help Concerning LED

    I use an automotive stop light led cluster with a suitable resistor.

    http://www.speeding.co.uk/acatalog/Car_Accessories_Hot_Spots___Assorted_Lighting_Prod ucts_108.htmlhttp://www.speeding.co.uk/acatalog/C...orted_Lighting _Products_108.html

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    • #3
      Help Concerning LED

      Ceri
      If you get stuck let me know. I work near a Maplins so I can pick you one up and post it.

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      • #4
        Help Concerning LED

        Ceri
        The voltage drop across the LED is about 2v so you want a resistor to drop 22v. They pull about 25mA or 25/1000 A. R=V/I so R= 22000/25 = 880 ohms. I use a 1K resistor in series with a superbright red LED in microCHIP and it works fine. If you send me an SAE together with a 50p coin Ill get one of my students to make one up for you.
        Rob
        Address:
        R H Jones, Product Design Dept, Denbigh High School, Ruthin Rd, Denbigh, LL16 3EX

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        • #5
          Help Concerning LED

          Hi,

          or buy a yellow 24v LED from Technobots?

          Mr Stu

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          • #6
            Help Concerning LED

            Or Buy a 24V Red,Green,Yellow or Blue one from RS or Farnell. Wont be as cheap or small as getting a standard LED and adding a resistor. Dont forget that 25mA at 22V is 0.55W so a standard 0.25W one wont do. I usually put to smaller resistors in each wire at the battery that way if either wire is shorted to anything you dont get any smoke.

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            • #7
              Help Concerning LED

              I knew the Resistance but not the wattage.

              I could make the circuit quite well, wasnt my problem. I was more worried about mounting/fitting. I hadnt planned on leaving transparency. as my robots design is heading towards being vunerable to spinners. (Much to my dismay - Dont know why Im letting this info to into little spinners hands...)

              How are the LEDs mounted to your machines?

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              • #8
                Help Concerning LED

                We use 5mm LEDs and a 5mm Hole & Super Glue, then filed the domed part of the LED off so its flush with the Armour. If it gets hit it simple gets pushed into the robot and then use a bit more super glue to fix it if it does go through the gears.

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                • #9
                  Help Concerning LED

                  AHHH the LED debate!!! *ducks and runs*

                  seriously though, i would just get the one from technobots, nice and easy to install. Just requires drilling a hole in the chassis, pushing it through then tightening a thin nut.

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