Anyone installed 12v internal lighting?
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    Quote Originally Posted by OwlHoot View Post
    HUH?!

    How can that be? I was told they use so little electricity you could practically leave them on all the time without worrying about your electricity bill.

    I mean that's the whole point of going with 12V bulbs surely (besides the not electrocuting yourself in the bathroom thing).

    edit: Or is it that LED bulbs use vastly less than conventional bulbs (e.g. filaments & fluorescent) but there isn't much difference in eleccy usage between LEDs at 12V and LEDs at 240V ?
    It's all about the wattage. Ohms law innit.
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    Quote Originally Posted by OwlHoot View Post
    HUH?!

    How can that be? I was told they use so little electricity you could practically leave them on all the time without worrying about your electricity bill.

    I mean that's the whole point of going with 12V bulbs surely (besides the not electrocuting yourself in the bathroom thing).
    OK, letís look at it like this:
    You pay for your electricity in kWh (thatís kilowatt hours)

    A 10 Watt LED requires 10W of power.

    Letís put 6 of them on a circuit (just to make my maths easier in my head). Thatís 60W of power.

    On a 12V circuit, you are using 60/12 = 5 amps
    On a 240V circuit, you are using 60/240 = 0.25 amps

    Youíre still using 60W of power, no matter what voltage of supply you use.
    But...
    To convert 240V down to 12V requires a transformer. Transformers are not 100% efficient. Letís say you have one running at 90%. That means you are losing 10% of power, so to get 60W to the lights, you need to put 65W in.

    240V lights = 60W
    12V lights = 65W for the same amount of light.
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    OK here's a simple example.

    I have a four horrible ("transport cafe c. 1970") fluorescent light fittings in my kitchen ceiling, and three of the four bulbs are on the blink, literally.

    Actually I think the fittings themselves are failing, because a brand new fluorescent bulb I fitted at the weekend also didn't work.

    So I'd like to rip all these out and replace them with LED strip lights (preferably dimmable). But looking at the "LED strip light" page at https://www.ledhut.co.uk/led-strip-lights.html, already my head is spinning with the bewildering complexity of it all!

    I mean there are literally dozens and dozens of LED widgets, and I've no idea what most do or why or when they would be needed

    Also, very few of the items on that page, in fact come to think of it none that I can see, look like actual light bulbs!

    So can anyone kindly suggest the best items of LED kit from that or another LED Hut page to replace a single fluorescent light fitting with the LED equivalent fitting in the ceiling and the LED bulb of equal brightness (equivalent to say a 120W incandescent bulb) ?


    edit: Studying that LED Hut strip light page some more, it appears that what they refer to as strip lights are those silly little "Christmas tree" lights like a tape measure with illuminated patches along it. But by strip light in the above I mean a proper LED replacement for a fluorescent light (if such things exist yet).
    Last edited by OwlHoot; 9th October 2017 at 16:48.
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    Default Anyone installed 12v internal lighting?

    Quote Originally Posted by northernladuk View Post
    It's all about the wattage. Ohms law innit.
    Um, no.

    Georg Ohmís law was V=I*R (Volts = Current (amps) * Resistance)
    Wattage doesnít come in to Ohmís law.

    P=V*I (Power (watts) = Volts * Amps)

    ...you should have asked your accountant electrician
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    Quote Originally Posted by OwlHoot View Post
    OK here's a simple example.

    I have a four horrible ("transport cafe c. 1970") fluorescent light fittings in my kitchen ceiling, and three of the four bulbs are on the blink, literally.

    Actually I think the fittings themselves are failing, because a brand new fluorescent bulb I fitted at the weekend also didn't work.

    So I'd like to rip all these out and replace them with LED strip lights (preferably dimmable). But looking at the "LED strip light" page at https://www.ledhut.co.uk/led-strip-lights.html, already my head is spinning with the bewildering complexity of it all!

    I mean there are literally dozens and dozens of LED widgets, and I've no idea what most do or why or when they would be needed

    Also, very few of the items on that page, in fact come to think of it none that I can see, look like actual light bulbs!

    So can anyone kindly suggest the best items of LED kit from that or another LED Hut page to replace a single fluorescent light fitting with the LED equivalent fitting in the ceiling and the LED bulb of equal brightness (equivalent to say a 120W incandescent bulb) ?
    I donít think you really want strip lights - those are ones where you can change colours, etc.

    You could start off with something as simple as replacing your fluorescent tubes with LED tubes, e.g.
    https://www.ledhut.co.uk/t8-18-watt-...0mm-3000k.html
    (Iím not an electrician, I donít know the size/model of your current tubes, but the above is just to give you an idea)
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    Quote Originally Posted by WTFH View Post
    I donít think you really want strip lights - those are ones where you can change colours, etc.

    You could start off with something as simple as replacing your fluorescent tubes with LED tubes, e.g.
    https://www.ledhut.co.uk/t8-18-watt-...0mm-3000k.html
    (Iím not an electrician, I donít know the size/model of your current tubes, but the above is just to give you an idea)
    Yes, I was about to post that I found an LED Hut page on what they call "tube lights", and these look like the fluorescent light replacements:

    https://www.ledhut.co.uk/commercial-...be-lights.html
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    Quote Originally Posted by OwlHoot View Post
    Yes, I was about to post that I found an LED Hut page on what they call "tube lights", and these look like the fluorescent light replacements:

    https://www.ledhut.co.uk/commercial-...be-lights.html
    Why would you want fluorescent tubes even if they are LED in your kitchen?
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    Quote Originally Posted by northernladuk View Post
    Why would you want fluorescent tubes even if they are LED in your kitchen?
    Well it has fluorescent tubes now, and I'm not a fan of fancy, poncey spotlights that light up the ceiling and leave the rest of the room in stygian gloom.

    Without wanting to sound facetious, I want to see clearly what I'm doing! Also, my kitchen is pretty large, about 30 by 20 feet. So a couple of normal LED bulbs probably won't cut it.

    But I'd also like dimmable LED tube lights, in case I don't want or need the full glare, and to save more electricity.
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    Quote Originally Posted by WTFH View Post
    Um, no.

    Georg Ohm’s law was V=I*R (Volts = Current (amps) * Resistance)
    Wattage doesn’t come in to Ohm’s law.

    P=V*I (Power (watts) = Volts * Amps)

    ...you should have asked your accountant electrician
    And since it be AC wot we're talking about, the Real Power is V*I*cos(theta).

    This is wot the old fashioned electricity meter records.

    Feck nose what these new fangled electronic meters record, but there is much muttering about them being strikingly inaccurate.

    <ZG in "pretending to be able to remember all this tulipe from 40 years ago and don't get me started on per unit calculations coz I never understood those to begin with" mode>

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    Quote Originally Posted by zeitghost View Post
    And since it be AC wot we're talking about, the Real Power is V*I*cos(theta).

    This is wot the old fashioned electricity meter records.

    Feck nose what these new fangled electronic meters record, but there is much muttering about them being strikingly inaccurate.

    <ZG in "pretending to be able to remember all this tulipe from 40 years ago and don't get me started on per unit calculations coz I never understood those to begin with" mode>
    Ah power factor calculations, them was the days....
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