convert from 12 volt to 6 volt

FreeBrrd
FreeBrrd Solar Expert Posts: 116 ✭✭✭✭
I feel stupid asking this, but I've forgotten & can't find anything on the internet. I want to use a 6 volt fountain water pump on a 12 volt system. I can't find a tiny 12 volt one, but lots of 6 volt ones.

thanks

Comments

  • GreenerPower
    GreenerPower Solar Expert Posts: 264 ✭✭✭✭✭✭
    Re: convert from 12 volt to 6 volt

    Search for something like this http://www.pacificcable.com/Picture_Page.asp?DataName=901-800, whether this one with 800ma is enough for the pump.
    GP
  • FreeBrrd
    FreeBrrd Solar Expert Posts: 116 ✭✭✭✭
    Re: convert from 12 volt to 6 volt

    Now I feel even dumber than I did asking. I've got several of those about.. somewhere. Nice thing about moving, I'm finding all kinds of things.

    Thank you.
  • FreeBrrd
    FreeBrrd Solar Expert Posts: 116 ✭✭✭✭
    Re: convert from 12 volt to 6 volt

    I was actually thinking more along the lines of if I put a resistor equal to the resistance of the pump in parallel or if I put a resistor in series. One way should half the voltage and the other should half the current ?? It's been a long time since I did any of that kind of stuff. I really prefer that to using a plug in deal.

    found it: http://www.play-hookey.com/dc_theory/voltage_divider.html
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: convert from 12 volt to 6 volt

    When converting voltages, there will be losses. Using a resistor, you get inaccurate voltage if the load deviates from the original calculation. If you use a LM7805 regulator, it's a smart resistor, but you still waste 50% of your power.

    You could use 2, 6V pumps in series, and pump 2x the water.

    And then there are Switcher Power supplies, which run 90% efficient, and cost a bit more. They can convert from 1 DC voltage to a different voltage
    Powerfab top of pole PV mount | 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 ,

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: convert from 12 volt to 6 volt

    Or get a small inverter and AC pump--the AC pumps may last longer too...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • FreeBrrd
    FreeBrrd Solar Expert Posts: 116 ✭✭✭✭
    Re: convert from 12 volt to 6 volt

    I've got a small inverter & an AC pump. Guess I'll use that. Should just use manual pump