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Adapter? Converter? Inverter? Help!

  1. Sep 24, 2008 #1
    Hello. I'm new here. I just discovered this fora thru Google and was hoping someone could help me. It will be obvious in a second that I'm not an engineer, so please pardon the silly/simple question:

    I have a device that was built for a car/RV that I want to run at home. (It's a wheelchair lift that normally goes onto an RV, but I installed it on my house so my father-in-law can get up the 4 steps into my house.) The lift runs on DC 12V. I would prefer not to power it via a car battery, but would like to "just plug it in."

    Can I "just plug it in?"
    If yes, what do I need?
    If no, why not?
  2. jcsd
  3. Sep 24, 2008 #2
    You need a mains power supply unit AC to 12 DC with sufficient output for the job.

    Do you know the current required in Amps or the power in Watts? Is there a plate on the device with this imformation?
  4. Sep 24, 2008 #3
    The installation instructions call for a 20 amp circuit breaker.
  5. Sep 24, 2008 #4
  6. Sep 24, 2008 #5
    PCS-125 is cheaper . 25 Amps (max) 4 - 15 volts and has terminals.

    PTS-124 is maybe better for your application.


    Available in many countries if you are not in Britain.

    Watson make a few suitable PSUs..


    Watson W-25SM looks OK. £80 in the UK.

    These are used to run professional and amateur radio euipment. If you have a ham radio shop near you they may have something adn will advise. Might help with interconnection problem. They tend to be knowledgeable people not just shop assistants.

    Where are you?
    Last edited: Sep 24, 2008
  7. Sep 24, 2008 #6
    I'm in the US, in NJ.

    Would my builder's electrician know what to do with either of these PSUs?
    Do I assume it's AC in one end and DC out the other (or vice versa depending on how you look at things).
  8. Sep 24, 2008 #7


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    The other (cheaper) solution is to use a car or (smaller) motorcycle battery, but keep the battery permanently connected to a standard automotive trickle charger that costs $20 from any auto parts store. You can put the battery and charger in a box and make it look nice, if that's a concern.

    And yes, the Watson PSUs plug into the wall just like any other household device.

    - Warren
  9. Sep 24, 2008 #8
    That's what my builder suggested :approve:
  10. Sep 24, 2008 #9
    I think motorcycle batteries are expensive and like car batteries have a finite life. High current batteries can be dangerous.. Terminals must be covered and you must have suitable fusing or a circuit breaker. A short circuit can be like an arc welder..blinding flash.,,,and thin wires can burn up.

    Lodi, NJ




    Mail: Hometek

    P.O. Box 263

    Lakehurst, NJ 08733

    E-mail: sales@cheapham.com (This is generally the quickest way to get a response from us!)

    Telephone 732-716-1600

    25 Amp PSU for $80. Jetstream JTPS28 28 amp Max, 25 amp Continuous Power Supply

    Last edited: Sep 24, 2008
  11. Sep 24, 2008 #10


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    In this application, the battery will last essentially forever. Dozens of years, if not more. The power supply units you suggest are safer, though, since they will fold back in the case of a short.

    - Warren
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