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LED sign 18v 1500mA

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  • LED sign 18v 1500mA

    I have an open sign that is 18v 1500mA, that runs on a 110 wall transformer. I would like to eliminate the long wire running to the outlet... enter solar technology.

    I am looking for the right panel..... but these things are listed by wattage.... so could someone point me in the right direction for one that will meet my needs?



    1 LED "Open" Sign requiring 18v @ 1500ma input. This thing is ran all day.... so its a power supply rather than a charger/tender


    There is not a lot of room for anything fancy, but I would like to add a capacitor so it can run for a couple of hours after sunset.... but this is purely optional


    Thanks in advance

    Anthony

  • #2
    Originally posted by 7rage View Post
    There is not a lot of room for anything fancy, but I would like to add a capacitor so it can run for a couple of hours after sunset.... but this is purely optional
    A capacitor will not do it, by a long shot. You need a battery, even if only for the after sunset hours. Also because having enough light to see by does not equate to producing much power from a panel, and I do not think you want the sign to turn on at 10am and off at 3pm.

    And if the sign is inside a window, forget about solar completely. You will lose 80% or more of your power that way, and the panel also needs to get direct sun, not just daylight.

    If having the sign visible at all times whey you are actually open is a requirement, stick to the long wire. Either on the 120v side or on the DC side.
    SunnyBoy 3000 US, 18 BP Solar 175B panels.

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    • #3
      Keep the cord. You do not want to pay for solar battery system.
      MSEE, PE

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      • #4
        the capacitor is not meant to make it last all day... that is the panels job....
        the sign is mounted to a door and the wire is ran around the door frame to an extension cord.... want to eliminate that because it's against code.. but the signs is best where it is (I've tried other spots, and I have limited windows space....) I can have a battery pack or a bank of caps, doesn't matter, but my ideal setup is more like a car....

        power comes from alternator to charge battery and run the car while its on.... not charge the battery, then hope to run sign off the battery all day....

        If a small controller board for a charging and power circuit is necessary then that's find... and if a bank of C or D batteries are needed then fine, but I cant mount a SLA battery on that glass looooool


        I mean if its really that out of the way to do it then whatever, my question would be answered.... but is there a manufactured panel that will power the device during daylight hours... like a 10 watt panel from amazon? people say they get 19v from meter but its a tender so I don't know if the sign will pull too much... I mean 1.5a isn't a whole lot, but I know it matters

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        • #5
          Originally posted by 7rage View Post
          I mean if its really that out of the way to do it then whatever, my question would be answered.... but is there a manufactured panel that will power the device during daylight hours... like a 10 watt panel from amazon? people say they get 19v from meter but its a tender so I don't know if the sign will pull too much... I mean 1.5a isn't a whole lot, but I know it matters
          The capacitor will not even last more than a few seconds at 1.5 amps.
          As for the panel size, you can work it out. 18 volts at 1.5A is 27 watts. So just to power the sign during full sunlight you would need about a 50 watt panel, and it would have to be higher voltage than the typical 12 volt battery tender or charger panel, since their maximum power voltage could easily go below 18 volts when the panel gets warm.

          Now if you are telling us 18 volts at 1.5 A just because that is what is written on the power supply block, there may be some hope that the actual draw of the sign is a lot less and more forgiving of voltage level.
          To even start a more detailed discussion we need at least three things:
          1. At what voltage does the sign start to look dimmer? (stops regulating the LED power to a fixed value)
          2. At what voltage does the sign go off completely? (hopefully not much above 12 volts)
          3. What current does the sign draw at 18 volts and at the low voltage just above the voltage in #2?
          SunnyBoy 3000 US, 18 BP Solar 175B panels.

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