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    Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first

    Adding LED lights to a coin door-Power supply question

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    led lightspower blockvoltageamps
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    • R
      robertm
      last edited by robertm

      Hi everyone,
      I am trying to ad some LED lights to light up my coin door return buttons.
      I purchased some ALLA Lighting T10/194 LED's and the specs call for 9V~30V and use 1.5 Watts per bulb.
      I have a power supply for 12Volts but they are way too bright. I tried a 6 volt, 500mA wall wart supply and it does light one of the LED's at a good brightness.
      My questions;

      1. Is it safe to run the LED's at the 6 Volt level?
      2. Is the 6 Volt/ 500 mA power supply strong enough to run TWO of these LED's without overheating? What safety factor is there, i.e. could it run 4 lights so I would have a safety factor of 2?
        I know these are pretty basic questions but haven't found an answer online.

      Thanks,

      Rob

      @robertm said in Adding LED lights to a coin door-Power supply question:

      12Volts

      F 1 Reply Last reply Reply Quote 0
      • F
        Folly @robertm
        last edited by Folly

        @robertm said in Adding LED lights to a coin door-Power supply question:

        Is it safe to run the LED's at the 6 Volt level?

        These are automotive led bulbs so they are not individual leds.
        So they contain some sort of current and voltage regulation inside.
        So with these leds you should be able to put these directly to a power supply.
        If 6 Volt works then why not use that if the brightness is good.
        With lower voltage they will use less current and will last longer and will be cooler.

        Is the 6 Volt/ 500 mA power supply strong enough to run TWO of these LED's without overheating? What safety factor is there, i.e. could it run 4 lights so I would have a safety factor of 2?
        I know these are pretty basic questions but haven't found an answer online.

        You say that the specs are 1,5 Watt but looking at the specs on internet they are 4 watts.
        Though you are running on a lower voltage with 6V so the brigtness is also lower so the current will also be lower.
        The current will probably be half.
        If not sure then use a multi-meter and measure the current :
        https://www.allaboutcircuits.com/uploads/articles/ammeter-illustration-1.jpg
        So they probably use 2 watts then you can calculate the current.
        The equation is P=U*I (power=voltage*current) so :
        2=6*I
        Therefor :
        I=2/6 = 0.3333...
        So running 2 bulbs on 1 power supply need 670mA.
        That is 170mA more than your power supply.
        So you can try to risk it and hope the practical spec, of your supply, are a bit higher than the theoretical one.
        Otherwise you have to get yourself a better supply.

        R 1 Reply Last reply Reply Quote 0
        • R
          robertm @Folly
          last edited by

          @Folly Thank you so much for the info!!!! I'm going to buy a better power supply.

          Rob

          1 Reply Last reply Reply Quote 0
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