When is 12v not 12v......?

Discussion in 'Motorhome Chat' started by Touchwood, Mar 5, 2013.

  1. Touchwood

    Touchwood Funster

    Joined:
    Aug 23, 2011
    Messages:
    749
    Likes Received:
    697
    Location:
    NE England
    I recently purchased a new tv for the MH, but it is 240v only - no problem as we are almost always on EHU. I'd like to feel though that we are truly independent if needs be, and have noticed that the tv at home in the kitchen (which we've had for a few years) is, in fact a 12v tv - it has a 240/12 v transformer to plug into the mains and the input on the back of the tv is labelled "12v dc"

    Is there any reason I can't swap the tv's and use the one from the kitchen on the MH 12v supply?

    I believe that with laptops, for example, it's important to use the correct mains transformer - is this just because they are not necessarily 12v? Or is there some other arcane electrical reason which means what I'm proposing could damage the tv?
     
  2. Johns_Cross_Motorhomes

    Johns_Cross_Motorhomes Trader - Motorhome & Accessory Sales

    Joined:
    Jan 5, 2008
    Messages:
    9,248
    Likes Received:
    5,199
    Location:
    East Sussex 01-580-881288
    No reason but the 12v supply is coming from the transformer on 240v EHU/Mains.

    You will need a lead correctly wired to get 12v from your leisure battery, I am sure PappaJohn can explain it more than me.

    Peter
     
  3. Snowbird

    Snowbird Funster Life Member

    Joined:
    Apr 24, 2009
    Messages:
    10,141
    Likes Received:
    16,396
    Location:
    Liverpool.
    As motorhome batteries can range from 11 volts to over 14 volts I always use a Maplin variable voltage supply lead set at 12 volts for the TV. Using one of these there should be no problem with your kitchen TV.
     
    • Like Like x 2
  4. Gromett

    Gromett Funster

    Joined:
    Feb 27, 2011
    Messages:
    7,941
    Likes Received:
    14,012
    Location:
    UK
    I will second Snowbirds comment. I see up to 14.5V on my battery terminals. I use a 12v regulator for any sensitive electronics.
     
    • Like Like x 1
  5. Touchwood

    Touchwood Funster

    Joined:
    Aug 23, 2011
    Messages:
    749
    Likes Received:
    697
    Location:
    NE England
    Many thanks - I've looked on the Maplins online stroe site and can only find this:

    http://www.maplin.co.uk/lm723c-variable-voltage-regulator-2347

    Is this what I need? Or is it something else?
     
  6. hilldweller

    hilldweller Funster Life Member

    Joined:
    Dec 5, 2008
    Messages:
    26,447
    Likes Received:
    25,131
    Location:
    Macclesfield
  7. Terry

    Terry Funster

    Joined:
    Dec 27, 2007
    Messages:
    10,722
    Likes Received:
    6,224
    Location:
    South yorks
    Or you can make up a lead and wire it directly to your battery or 12v plug/ariel :Wink:
    terry
     

    Attached Files:

  8. Snowbird

    Snowbird Funster Life Member

    Joined:
    Apr 24, 2009
    Messages:
    10,141
    Likes Received:
    16,396
    Location:
    Liverpool.
    It has multi voltages and different tips to suit whatever you want to run from it. Sorry I dont have a link but they were on offer a few weeks ago. If you have a store close bye then they should have them on the shelf. I think its called a stabilised voltage supply. They are not expensive, but could save you a lot of expense and I have used mine a lot so can recommend.
     
  9. Sidney

    Sidney Funster

    Joined:
    Jan 27, 2013
    Messages:
    1,084
    Likes Received:
    690
    Location:
    Stamford
    Yes. I've done this without any issues but I've never had an expensive "motorhome" TV. Apparently some manufacturers make noise that you must use a regulated supply or the warranty is invalid - but this is often quoted by those selling regulated supplies. :RollEyes:

    Many plug-top and in-line DC supplies vary wildly from the stated voltage with some giving 17 volts - that's a 40% variation with no apparent impact.
     
  10. Terry

    Terry Funster

    Joined:
    Dec 27, 2007
    Messages:
    10,722
    Likes Received:
    6,224
    Location:
    South yorks
    The battery itself works as quite a good stabiliser :thumb:Never had a problem over the last 12 yrs or so -always been wired direct to battery/ariel plug
    terry
     
    • Like Like x 1
  11. Touchwood

    Touchwood Funster

    Joined:
    Aug 23, 2011
    Messages:
    749
    Likes Received:
    697
    Location:
    NE England
    That's the job. Two ordered. Many thanks to all.:Smile:
     
  12. callumwa

    callumwa Read Only Funster

    Joined:
    Jan 16, 2011
    Messages:
    4,113
    Likes Received:
    4,517
    Location:
    Tyne & Wear, sometimes..
    I have an Avtex in the van but also fitted a cheap flat screen TV/DVD (£99) in front of the travel seats for the boys to watch whilst travelling.

    I just made up a simple 12v lead consisting of a cigarette plug at one end and the right plug for the Tv at the other in lieu of the 240v transformer.

    12v system ranges from about 12.1 to 14.1 V on the NASA BM-1

    Tv has been working perfectly for 3 years.....

    Still as good as new. No need for additional fancy regulated stabilised things etc.......:thumb:i
     
  13. rainbow chasers

    rainbow chasers Read Only Funster

    Joined:
    Oct 30, 2009
    Messages:
    3,747
    Likes Received:
    1,720
    Location:
    Mid Cornwall
    You will need a voltage stabiliser to iron out any 'spikes' in the supply or else you will damage the TV. You won't have any issues though once you have this - they work perfectly well.
     
  14. dave newell lvs

    dave newell lvs Trader-Vehicle Services

    Joined:
    Oct 31, 2008
    Messages:
    2,515
    Likes Received:
    3,319
    Location:
    Telford, Shropshire
    The voltage stabiliser's job is nothing to do with "spikes" it is simply there to give a regulated 12 volt output. Some domestic TVs (not all but some) have the voltage regulation built into the 230v/12v power brick, the TV itself in this case often has no voltage regulation and can be sensitive to voltages in excess of 12volt DC. I have personally seen plenty of domestic TVs of this nature with blown backlights because they were run from a motorhome's battery without voltage regulation.

    The multi voltage regulator from Maplin needs to be used with caution as it is only the lower voltages that are regulated, the 12v setting is in fact a direct pass through with no regulation whatsoever.

    D.
     
    • Like Like x 1
  15. hilldweller

    hilldweller Funster Life Member

    Joined:
    Dec 5, 2008
    Messages:
    26,447
    Likes Received:
    25,131
    Location:
    Macclesfield
    10V -> 15V that's stretching the word "stabilise" a bit.

    I'm one of the direct connect people, but I have a good chance of fixing it if it blows up, which the Kogan has not in 2 years now.

    Well I did blow it up, by reversing the polarity when I repositioned the TV recently, luckily it just popped a soldered in fuse. Damned Germans - they got me - brown wire = 0V. I knew this, but brain fade kicked in.
     
    • Like Like x 1
  16. callumwa

    callumwa Read Only Funster

    Joined:
    Jan 16, 2011
    Messages:
    4,113
    Likes Received:
    4,517
    Location:
    Tyne & Wear, sometimes..
    Motorhome Voltage Stabilisers,

    Motorhome TV's

    Motorhome Leisure Batteries,

    Motorhome Food Grade Fresh Water Hoses,

    Motor Home Cassette Toilet Chemicals,

    Motorhome GPS......

    Just some of the many ways to try and get Motorhomers to uneccesarily part with even more of their hard earned cash...

    :Doh:
     
    • Like Like x 2
  17. Sidney

    Sidney Funster

    Joined:
    Jan 27, 2013
    Messages:
    1,084
    Likes Received:
    690
    Location:
    Stamford
    It could be worse. You could have a boat :Eeek:
     
    • Like Like x 2
  18. Reallyretired

    Reallyretired Funster

    Joined:
    Apr 27, 2008
    Messages:
    5,706
    Likes Received:
    3,211
    Location:
    Eastbourne East Sussex
    I've used a 12v TV (cheap from Comet) for 12 years without a stabiliser, in 4 different vans. It has an external digital TV box as it wasn't invented when I bought the TV but is still going strong.
     
  19. pappajohn

    pappajohn Funster Life Member

    Joined:
    Aug 26, 2007
    Messages:
    29,474
    Likes Received:
    16,940
    Location:
    YO11 2BD
    aint that the truth :Sad:

    stick the word 'motorhome' in front of a pisspot and the price doubles. :Angry:
     
    • Like Like x 1
  20. mitzimad

    mitzimad Funster

    Joined:
    Jan 28, 2008
    Messages:
    2,970
    Likes Received:
    3,320
    Location:
    walthamstow east london
    substitute the word marine instead of motor home and quadruple the price add the word yacht and double it again
     
    • Like Like x 1
Loading...
Similar Threads
  1. Touchwood
    Replies:
    10
    Views:
    286
  2. haddy
    Replies:
    8
    Views:
    301
  3. emilu
    Replies:
    20
    Views:
    752
  4. landyman
    Replies:
    19
    Views:
    866
  5. lorger
    Replies:
    14
    Views:
    876

Share This Page