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Power audio amp off lighting circuit via transformer?

Discussion in 'Electrics UK' started by SteUK, 6 Apr 2013.

  1. SteUK

    SteUK

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    Hi chaps/chappettes,

    Wonder if I could get a bit of knowledge about the best way to rig up an audio amp in my loft.

    I want to drive a pair of speakers from a small audio amp (12v, 2amp : peak amp output is 2x20W), but only want the amp 'on' when the lights are on. Can I treat it the same as the low voltage lights I currently have lighting the room? i.e. hook up a transformer to the lighting circuit and power it off the transformers output?

    Obviously safety comes first and I don't want to be doing something that is not 110% safe and correct.

    Cheers for your advice!

    Ste
     
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  3. davelx

    davelx

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    A transformer will not work. I'm guessing it's a car audio amp? It will need a reasonably well regulated DC supply of suitable rating. Best consult the place you bought it from. I'll let others comment on connecting to the lighting circuit :)

    It's impossible for something to be more than 100% safe or correct. It's pretty much impossible for anything to be 100% safe. :mrgreen:
     
  4. ban-all-sheds

    ban-all-sheds

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    Why not look on ebay for a small stereo system which is meant to be used in a house not a car?
     
  5. SteUK

    SteUK

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    Cheers for the responses :)

    The ones I have been looking at come with AC power adapters, but I am not sure I want to be fuse spuring a socket off the lighting circuit. I am pretty sure that is not good practice.

    Why not just spur off the upstairs ring main? I want it to only be on when the lights are on...my limited knowledge tells me that cannot be achieved if hooked up to the sockets circuit.
     
  6. OwainDIYer

    OwainDIYer

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    Without some complicated switching you will not get the amp to operate when 'any' light is on, but only when a specific light is on i.e. wired in parallel to the switched live for that light.

    13A sockets should not be wired off the lighting circuit so get a power supply that has a mains flex end and wire it to a 3A fused spur off the lighting circuit.

    If it's a Lepai style digital amp 20+20 watt will usually require closer to a 12V 5A DC supply not a 12V 2A DC supply.
     
  7. SimonH2

    SimonH2

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    I can't see why a 13A socket can't be used - suitably labelled. Worst case is that someone plugs in a larger load and trips the circuit protection.

    As an alternative, fit a 5A socket. Of course, no-one would think of making up a short lead with a 13A trailing socket and a 5A plug ;)
     
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  8. mikhailfaradayski

    mikhailfaradayski

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    Just curious, but is there a reason why the amp should only work with the light?
    Is there no requirement for sound during the day?
     
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