Announcement

Collapse
No announcement yet.

Why do I need an inverter -> transformer?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Why do I need an inverter -> transformer?

    Here is my setup: (2) 75Watt, 12V panels ==> charge controller ==> 12V batteries ==> 750 Watt inverter ==> transformer (came as part of a lighting kit) ==> (5) 12v 30 watt LED landscape lights. The transformer has settings for lighting dusk-to-dawn or selected hours or always on plus motion detection. The inverter takes 12V in and puts 120V out so I can plug in the transformer, which converts back to 12V to feed the lights. It seems like I should be able to replace the functions of the transformer and eliminate the inverter. Does anyone know of a 12v device that can do what this 120V transformer does?
    http://www.rockvalleynaturalstone.co...cb-081m-detail

  • #2
    If your lights run off 12Vdc, then the Sunlight controller would manage turning the lights off and on, within it's amps limits
    https://www.morningstarcorp.com/products/sunlight/
    It does [B]not [/B]have motion sensor
    Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister

    Comment


    • #3
      I am buying 12 volt motion sensors from Amazon for about $12 each. I'll post a lead to what I am using if requested. These output 12 volts when triggered , haven't got a dead one yet. They would be suitable for your use along with a timer. I know of no device which combines both functions into one device. My internet is dead slow at this location so I can't go to amazon from here. Do avoid a double conversion of 12 volts to 120 volts then back down to 12 volts.
      david

      Comment


      • #4
        Originally posted by Bounty Hunter 23 View Post
        ......... Does anyone know of a 12v device that can do what this 12v transformer does?
        First I would check the "transformer" to see if it puts out AC or if it puts out DC, in which case it should be called a power supply. Your LEDs run on DC and they can have a narrow range of current and voltage at the LED level. Some where in your light string is where voltage and current are regulated. My point is you may shorten the life of your LEDs if you are not careful. It may be less expensive to get 12v DC LEDs and use a Sunlight controller as Mike suggested.

        Comment


        • #5
          Originally posted by Ampster View Post
          First I would check the "transformer" to see if it puts out AC or if it puts out DC,.
          Click the link, it is a 100 watt Inverter.

          OK take the 100 watt Inverter and toss it in the trash. Keep the box as it may have some use. Second Issue is your 750 watt Inverter is way too large. An Inverter that size requires at minimum 500 watts of panels and a 12 volt 500 AH 300 pound battery so the 750 watt Inverter is not of much use either. With a 150 watts of panels can only support a 12 volt 75 to 100 AH battery and 200 wat Inverter.

          As Mike pointed out use your charge controller if it can handle a 5 amp load.You have no use for Inverters. You want to run straight 12 volt DC.



          MSEE, PE

          Comment


          • #6
            Mike,
            It looks like that product you suggested is exactly what I was looking for. The motion detection would be nice, but is not a deal breaker. I can pick that thing up for $50 on ebay.

            Ampster,
            The referred to the transformer I currently use as a "transformer" because that is what the manufacturer called it. The thing plugs into a standard 110v plug (or inverter) and outputs 12v DC.

            Thank you to all for your assistance!

            Comment


            • #7
              Originally posted by Sunking View Post
              Click the link, it is a 100 watt Inverter.
              ..................You have no use for Inverters. You want to run straight 12 volt DC.


              Are we looking at the same link? The link did not call it an inverter nor did it specify voltage. It just said 12v/108Watt

              The original poster did answer my question. The issue that is still unresolved is whether the string of LED lights takes DC of AC. If they take AC there may be a rectifier in the lights or the string to power the LEDs which take DC.

              I agree with you that running 12v DC is the answer.
              Last edited by Ampster; 05-28-2019, 02:11 PM.

              Comment


              • #8
                Originally posted by Bounty Hunter 23 View Post
                .....
                Ampster,
                The referred to the transformer I currently use as a "transformer" because that is what the manufacturer called it. The thing plugs into a standard 110v plug (or inverter) and outputs 12v DC.
                I don't see anywhere is says that it outputs DC? Have you checked the output for polarity?

                EDIT: I found this link that says the output is 12v AC.
                https://in-sider.com/collections/our...8w-transformer

                So you do need an inverter or a new string of lights that takes 12VDC to efficiently run your 12VDC battery and solar panel. I understand that transformer costs over $100 so I understand why you would want to use it.
                Last edited by Ampster; 05-28-2019, 03:04 PM.

                Comment

                Working...
                X