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12v Fan

Former Community Member
Former Community Member
I am fitting a fan for a friend which is going to be in zone 1, opposite side of bath/shower, is there a fan which is suitable for this? It is about 6ft up from the bath, it’s a small room. I’ve looked at the low volt ones but the transformer is to big, which I have no where to hide it. Do they do them with smaller transformers? Possibly 230v one?


The fan won’t be needing a time delay as to limit any damage they just wanted it to come on and straight off with the light.


clint
  • 0
    Be aware that a lot of so called "lighting transformers" are not transformers at 50Hz at all, especially the lightweight ones, rather there is a rectifier that takes the mains to DC and some power transistors that chop it into a square wave at a supersonic frequency, and apply it to a transformer with a much smaller and lighter core than would be possible to shift the same power at 50Hz. This saving in copper and iron costs justifies the complexity, especially at higher wattages.

    Lights generally do not care, as filaments will heat up on 50KHz just as easily as 50Hz, and LEDs rectify it anyway.

    However some 12V fans are shaded pole motors with shorter fatter windings than their mains relatives, and really do need a nice sine wave at the right frequency to rotate at all - for these a conventional iron and copper transformer is required not a so called 'electronic transformer'..
  • Former Community Member
    0 Former Community Member

    mapj1:

    Be aware that a lot of so called "lighting transformers" are not transformers at 50Hz at all, especially the lightweight ones, rather there is a rectifier that takes the mains to DC and some power transistors that chop it into a square wave at a supersonic frequency, and apply it to a transformer with a much smaller and lighter core than would be possible to shift the same power at 50Hz. This saving in copper and iron costs justifies the complexity, especially at higher wattages.

    Lights generally do not care, as filaments will heat up on 50KHz just as easily as 50Hz, and LEDs rectify it anyway.

    However some 12V fans are shaded pole motors with shorter fatter windings than their mains relatives, and really do need a nice sine wave at the right frequency to rotate at all - for these a conventional iron and copper transformer is required not a so called 'electronic transformer'..




    Thanks for that response, I won’t be trying that one.

  • 0

    Clint:

    Can you use a lights transformer? I found a 12v fan at a decent price but it doesn’t come with transformer, if I can get away with a light transformer, I could put this in the ceiling at the size of them. 




    Unless you us a SELV transformer you are back to where you started, you could end up with 230 bolts at the fan.


    So you need to use the correctly rated transformer that is marked as SELV.


    Andy Betteridge 

  • 0
    230 volts.


    Flamin’ spellchequer.


  • 0

    whjohnson:

     the building regs changed, and now you have to fit mechanical ventilation, even if there is the facility of opening a window instead.

     



    Are you sure?


    Part F (1) merely states that "There shall be adequate means of ventilation provided for people in the building". 


    It is as equally undemanding as Part P.


  • 0
    Now,now!


    I have been resisting asking if the job is in Wales.


     Andy B.

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