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HELP: halogen vs energy-saving light bulb.... woes :S

Discussion in 'Electronic Basics' started by KevinGPO, Dec 29, 2005.

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  1. The transformers were/are specifically for halogen lighting (my typo -
    thinking about the spelling of fluor/flour ..escent and not checking
    what I wrote..).


    One is clearly electronic - it is too light to be anything else.

    The other has a data sheet saying it is a "lighting encapsulated
    toroidal transformer".

    Unfortunately the latter *is* encapsulated, so I can't tell how the
    output voltage is limited. But it clearly is - as increasing the input
    voltage doesn't produce a corresponding increase in output voltage. The
    encapsulation looks to be a fair bit bigger than to be holding just the
    transformer and one end is much heavier than the other.

    Any transformer experts? I did wonder if it had an additional winding
    with some voltage-sensing electronics, or just had a shunt-type
    regulator or did it with fancy saturation characteristics..
     
  2. LOL. Thanks for that - Perhaps I only get to see better quality light
    fittings!

    I have one of those wire-strung setups, but it uses a dimmable
    electronic transformer ( A dimmer is inline in the mains lead) and each
    lamp fitting has its own on/off switch.

    The single-lamp fittings I have all have their own individual
    transformer, too. Judging by the weight - they are electronic, too.

    Presumably the light strings powered by a conventional transformer don't
    have individual switches for the lamps?
     
  3. James Sweet

    James Sweet Guest

    No, it's a typo.
     
  4. James Sweet

    James Sweet Guest

    Nor have I, but I have seen plenty that were single lamp fixtures so he
    could have a number of those in a room.
     
  5. James Sweet

    James Sweet Guest


    If they're recessed can fixtures, you should be able to replace them
    with fixtures that have a conventional light socket in them. I'm not
    sure about where you are, but here in the US you can get cans designed
    for remodel jobs where you cut the hole in the ceiling to the correct
    size, connect the wire to the junction box mounted to the fixture, and
    then stick the whole assembly up into the ceiling and snap down the
    levers that latch it into place.

    You could also get a conventional surface mount fixture that's large
    enough to cover the hole from the halogen fixture, but you'll probably
    need to figure out a way to mount a junction box for the fixture to
    attach to unless the existing holes are small enough to accommodate a
    remodel box.
     
  6. Dave D

    Dave D Guest

    Any fitting with a iron cored transformer and no regulation circuitry will
    suffer this effect. I've only personally ever seen switchmode types with
    regulation, never an iron cored regulated type. Even some switchmode
    halogens are not truly regulated as they are designed to be dimmed. The
    output varies with the input on those types.

    Probably? We don't know that, do we? I thought it was worth mentioning in
    case they are the type which may be affected. A huge chunk of LV
    multi-light halogen fittings sold here in the UK use nothing more fancy than
    a standard iron cored transformer, running close to its electrical limit.
    The only thing keeping the voltage down to approx 12V is the correct load on
    the transformer.

    If the advice is not pertinent to the OP then that's fine, I didn't know
    what type of light he had so I made a guess. However it is pertinent to
    anyone with an el cheapo DIY type iron cored transformer based halogen multi
    light fitting.

    Dave
     
  7. Dave D

    Dave D Guest

    Yep, it's possible.

    Here in the UK, these multi-light single halogen fittings are becoming
    enormously popular, and most of them use a single iron cored transfomer. I
    thought my advice might be of interest in general to anyone with these
    lights.

    Dave
     
  8. Yep, certainly agree. I hadn't realised that many/most light fittings
    with multiple halogen lights didn't have transformers specifically
    designed for halogen lighting. Thanks. The one I have is, from what you
    have said, unusual and my fault for assuming that all were like that..
    That "assume" word - you would think I was old enough to know better..


    Same with my "probably". I hadn't allowed for market pressures!

    Whether the OP's fittings take multiple lights, or are strung out from a
    common transformer(s), or have individual transformers, or have mains
    rated lamps, is another matter. What he apparently has is wires hanging
    from the ceiling.. So whether the fitting that was there had multiple
    lights or not has become a little academic.. unless, as you say, they
    chain back to a common transformer.
     
  9. Dave D

    Dave D Guest

    I personally have both types, and I have to say the switchmode type is much
    nicer. My iron transformer ones have noticeably shorter lamp life. The
    switchmode one, apart from being much lighter, has a soft start which ramps
    the lamps up to full brightness over a couple of seconds. I know they say
    that soft start has a negligable effect on lamp life, but I have yet to
    change a bulb in this fitting and it's been up three years! I don't know if
    it's dimmable or not.
    I also made an assumption, I don't think given the lack of technical details
    that we had much choice!
    I've certainly seen a shift towards switchmode types recently, which I
    suppose is a mixed blessing.
    Hopefully they are individually powered lights, it makes things much easier.
    Especially if a common transformer fails! That happened to my friend, who
    very unwisely fitted his 10-light transformer into a ceiling cavity of a
    newly lowered ceiling. It's a couple of years now and he still hasn't had
    the heart to smash a hole in his new ceiling and sort it out!

    Dave
     
  10. Guest

    I think you need to consult your landlord.

    In some apartments the lighting is on a seperate circuit and included
    in your monthly rent.
     
  11. Pooh Bear

    Pooh Bear Guest

    Many of the modern lighting 'transformers' are actually small switched mode power
    supplies. Their output voltage won't vary much with loading. A conventional line
    frequency transformer *will* vary with loading though.

    Graham
     
  12. Pooh Bear

    Pooh Bear Guest

    No way.

    Unlikely actually to be a toroidal transformer at all.

    Graham
     
  13. Pooh Bear

    Pooh Bear Guest

    'Conventional' transformers were widely used for low voltage lighting until
    switch-mode supplies became competitive. They *were* specifically designed for
    such use.

    Graham
     
  14. Pooh Bear

    Pooh Bear Guest

    Those transformers *were* designed for purpose. However a plain ordinary
    transformer's output voltage will vary with load.

    Graham
     
  15. I have two here.

    One is *much* heavier than the other, each with much the same rating.

    It is labelled as a toroidal transformer. The manufacturer's data sheet
    describes it as a toroidal tranformer.

    It does, however, not behave like a conventional transformer. The output
    voltage rises near enough linearly with the supply voltage, but at 11.4v
    rms out (215 v in) the rate of increase slows and the output is still
    below 12v at 260v input (my variac won't go higher).

    The "light" end gets warm - and gets hot quite quickly if left on 260v.

    I will stick it on a scope tomorrow and see what the output waveform
    looks like.

    Shame it is encapsulated.
     
  16. The lighting transformer (a toroidal transformer specifically designed
    for halogen lighting), that I have, do not look at all like conventional
    transformers, either toroidal or not. I cannot see why they have what
    appears to be a "light" end as large as they have - unless it is to hold
    some form of additional components. They are far too heavy to be a
    switch mode psu of the same rating - unless the designer added a bit of
    extra weight for marketing purposes!

    They certainly do not have the transfer function that I would expect
    from a conventional transformer.
     
  17. Given that I don't see or hear about those particular transformers
    (12V wattage around 80 or 100 watts or current about 7 or 8 amps) turning
    up in much of anything besides halogen lighting, I think they are designed
    specifically for halogen lighting - just cheaply.

    - Don Klipstein ()
     
  18. Rich Grise

    Rich Grise Guest

    Me, too.
    I've seen paraffin lamps (liquid paraffin), and kerosene lamps, but I
    haven't seen either of those fuels used in a lamp with a mantle - only
    gas (like propane) and the Coleman white-gas[oline] camping lanterns,
    which are painfully bright, and uncomfortably hot.

    How would you use paraffin or kerosene in a mantle lamp?

    BTW, the difference as I know it is that "pure" paraffin burns cleanly,
    with a smokeless flame, exactly like a candle, but a kerosene flame,
    if it's not sooty, it's still ugly yellow and it stinks. I think you
    need some kind of forced air to get kerosene to burn "clean".

    Thanks,
    Rich
     
  19. John G

    John G Guest

    You must be too young.

    Try this site http://www.tilleylamp.co.uk/

    If I remember correctly you had to warm it up with methylated spirits
    (alcohol) to get the kerosene vaporised to burn properly but once
    started the mantle provided the heat for vaporisation.
     
  20. Jasen Betts

    Jasen Betts Guest

    ["Followup-To:" header set to sci.electronics.basics.]
    for a start you need a mantle lamp that's made for kerosene.
    these have a pressure canister in the base and after filling it with kerosene
    you pump air into it to provide pressure, then you need to heat the mantle
    and the pipes leading to it lamp using a clip on thing dipped in metholated
    spirits (which you light)

    when the meths has almost burned out you turn on the valve and the kerosene
    rises up the pipe and is vaporised before entering the mantle.

    once the mantle lights up the clip comes off and goes back in the jar of
    meths

    sometimes the mantle wouldn't light up and instead there'd be a yellow
    flame, in that case you'd need to replenish the meths and and warmm the
    lamp up some more.

    one brand of these kerosene maltle lamps was "Tilly" IIRC, but Coleman made
    them too.

    IIRC the coleman version had a well that you filled with metholated spirits
    instead of the clamp on wick.
    ah... so it'd be paraffin that gets used in those fog machines...

    the "fog" smells like cnadles.

    Bye.
    Jasen
     
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