Driving miniature TL flou

Discussion in 'Lighting' started by Richard, Jul 27, 2008.

  1. Richard

    Richard Guest

    I bought a cheap flourescent luminair. Works of 12 VDC 500mA.

    I took it apart because I thought the lamp inside is about the right size
    for a project. Ballast is electronic on a small PCB, only a few descrete
    components. Obviously the ballast is cheap to make.

    Inside is an unbranded T5 lamp of 8W. It's 288mm long so it is a mini TL
    lamp. Two pins on each end.

    Looking at Philips technical site I see that the recommended ballast for
    this kind of Philips lamp/lamp would be type BPL 02W. This ballast is a
    simple inductor. It's compactish, 85mm x 39mm x 28mm. Wiring is standard
    when using a choke and a starter.

    But, the electronic ballast in this luminaire does not employ the heaters.
    Pins at both end are joined together.

    I suppose that whether employing the cheap electronic ballast or the choke,
    the lamp gives the same light output. True? But for economy, I guess one
    would always go with the proprietry electronic ballast. Although mains
    working would require a step doen transformer. So, cost savings would
    not materilise - perhaps.

    Not sure about any differences in lamp protection and safety.

    I just get to wondering when I come across this kind of thing why anyone
    would select the choke ballast.
    Richard, Jul 27, 2008
    #1
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  2. Richard

    Richard Guest

    "Richard" <> wrote in message
    news:...
    >I bought a cheap flourescent luminair. Works of 12 VDC 500mA.
    >
    > I took it apart because I thought the lamp inside is about the right size
    > for a project. Ballast is electronic on a small PCB, only a few descrete
    > components. Obviously the ballast is cheap to make.
    >
    > Inside is an unbranded T5 lamp of 8W. It's 288mm long so it is a mini TL
    > lamp. Two pins on each end.
    >
    > Looking at Philips technical site I see that the recommended ballast for
    > this kind of Philips lamp/lamp would be type BPL 02W. This ballast is a
    > simple inductor. It's compactish, 85mm x 39mm x 28mm. Wiring is standard
    > when using a choke and a starter.
    >
    > But, the electronic ballast in this luminaire does not employ the heaters.
    > Pins at both end are joined together.
    >
    > I suppose that whether employing the cheap electronic ballast or the
    > choke,
    > the lamp gives the same light output. True? But for economy, I guess one
    > would always go with the proprietry electronic ballast. Although mains
    > working would require a step doen transformer. So, cost savings would
    > not materilise - perhaps.
    >
    > Not sure about any differences in lamp protection and safety.
    >
    > I just get to wondering when I come across this kind of thing why anyone
    > would select the choke ballast.


    Although it occurs to me that I bought that luminaire that's run off 12V. I
    think I could be mixing apples and oranges a bit here.
    Richard, Jul 27, 2008
    #2
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  3. Richard

    TKM Guest

    "Richard" <> wrote in message
    news:...
    >I bought a cheap fluorescent luminair. Works of 12 VDC 500mA.
    >
    > I took it apart because I thought the lamp inside is about the right size
    > for a project. Ballast is electronic on a small PCB, only a few descrete
    > components. Obviously the ballast is cheap to make.
    >
    > Inside is an unbranded T5 lamp of 8W. It's 288mm long so it is a mini TL
    > lamp. Two pins on each end.
    >
    > Looking at Philips technical site I see that the recommended ballast for
    > this kind of Philips lamp/lamp would be type BPL 02W. This ballast is a
    > simple inductor. It's compactish, 85mm x 39mm x 28mm. Wiring is standard
    > when using a choke and a starter.
    >
    > But, the electronic ballast in this luminaire does not employ the heaters.
    > Pins at both end are joined together.
    >
    > I suppose that whether employing the cheap electronic ballast or the
    > choke,
    > the lamp gives the same light output. True? But for economy, I guess one
    > would always go with the proprietry electronic ballast. Although mains
    > working would require a step doen transformer. So, cost savings would
    > not materilise - perhaps.
    >
    > Not sure about any differences in lamp protection and safety.
    >
    > I just get to wondering when I come across this kind of thing why anyone
    > would select the choke ballast.


    Fluorescent lamp ballasts have two main functions (1) start the lamp (2)
    control the current through the lamp. A choke ballast works just fine if
    there's already enough voltage available from the supply line for starting.

    When the lamp pins are shorted together, the starting mode is likely to be
    what's called "instant start". That starting mode uses the available
    voltage to ionize the gas in the lamp. When the current starts flowing, the
    lamp cathodes get hot and the lamp current stabilizes at some value
    determined by the external ballast circuit (choke or electronic current
    limiter).

    In your situation since the fixture is designed to be powered by 12 volts,
    there's an inverter someplace that transforms the 12 volts dc to high
    voltage and, probably, high frequency ac.

    The key factors to determine if you're building your own ballast are the
    lamp's current rating, and starting voltage.

    Terry McGowan
    TKM, Jul 27, 2008
    #3
  4. In article <>,
    "Richard" <> writes:
    > I bought a cheap flourescent luminair. Works of 12 VDC 500mA.
    >
    > I took it apart because I thought the lamp inside is about the right size
    > for a project. Ballast is electronic on a small PCB, only a few descrete
    > components. Obviously the ballast is cheap to make.
    >
    > Inside is an unbranded T5 lamp of 8W. It's 288mm long so it is a mini TL
    > lamp. Two pins on each end.
    >
    > Looking at Philips technical site I see that the recommended ballast for
    > this kind of Philips lamp/lamp would be type BPL 02W. This ballast is a
    > simple inductor. It's compactish, 85mm x 39mm x 28mm. Wiring is standard
    > when using a choke and a starter.
    >
    > But, the electronic ballast in this luminaire does not employ the heaters.
    > Pins at both end are joined together.


    Many of those cheap battery inverters don't drive the tube
    very well. The lack of preheating will result in fewer starts,
    but worse, they often significantly under-run the tube, meaning
    the filaments don't get as hot as they should, ant this also
    reduces tube live. Often doesn't matter with battery lights as
    they aren't operated for that long (battery replacement price
    and frequency would become a significant issue).

    > I suppose that whether employing the cheap electronic ballast or the choke,
    > the lamp gives the same light output. True? But for economy, I guess one


    As I said, many of those cheap battery inverters significantly
    under-run the tube, and get short tube life as a result.

    > would always go with the proprietry electronic ballast. Although mains
    > working would require a step doen transformer. So, cost savings would
    > not materilise - perhaps.
    >
    > Not sure about any differences in lamp protection and safety.
    >
    > I just get to wondering when I come across this kind of thing why anyone
    > would select the choke ballast.


    They are cheap. It's also worth pointing out that the 4/6/8W T5
    tubes don't work very well on 240V series ballasts with glow
    starters. Two things are non-optimal - the 240V mains voltage
    can sometimes instant-start them before the filaments get heated up,
    but if it doesn't, it can take quite a bit of flashing to get them
    started. Glow-start works well with all tubes from 24" upwards
    on 240V, but not with the very short tubes.

    I would suggest you get a Philips MF-Matchbox 109 ballast. This
    is a mains electronic ballast for this tube. It comes in two
    types, Blue which is instant start, and Red which is preheat.
    Preheat will give longer tube life in the case of frequently
    switching on and off. Instant start may be preferable where
    you don't want a second or so starting delay and either don't
    switch on and off frequently or don't care about the reduction
    in tube life. Both types require 4 connections to the tube and
    power the filaments (unlike US instant-start circuits). Each
    type is available in 2 shapes -- a matchbox, or a longer thinner
    box (more suitable for going into a thin T5 fitting), and both
    these are also available as just the bare circuit board too.

    RS do the Blue cased ones for around £7 (+ VAT/P&P):
    http://uk.rs-online.com/web/search/...od=searchProducts&searchTerm=philips matchbox

    The other thing you might be interested in is making your own
    ballast from an old CFL. There are some notes here:

    http://www.cucumber.demon.co.uk/lights/diy/

    The following shows the Philips matchbox ballast retrofitted
    into a light and driving a 10W 2D lamp

    http://www.cucumber.demon.co.uk/lights/diy2/

    --
    Andrew Gabriel
    [email address is not usable -- followup in the newsgroup]
    Andrew Gabriel, Jul 27, 2008
    #4
  5. Richard

    Guest

    Richard <> wrote:
    > I bought a cheap flourescent luminair. Works of 12 VDC 500mA.


    There are some schematics for inverters designed to run small
    fluorescent tubes off of low-voltage DC at
    http://www.repairfaq.org/sam/samschem.htm#schamt
    that you might find interesting.

    Matt Roberds
    , Jul 27, 2008
    #5
  6. Richard

    Richard Guest

    "Andrew Gabriel" <> wrote in message
    news:488c83e2$0$755$...
    > In article <>,
    > "Richard" <> writes:
    >> I bought a cheap flourescent luminair. Works of 12 VDC 500mA.
    >>
    >> I took it apart because I thought the lamp inside is about the right size
    >> for a project. Ballast is electronic on a small PCB, only a few descrete
    >> components. Obviously the ballast is cheap to make.
    >>
    >> Inside is an unbranded T5 lamp of 8W. It's 288mm long so it is a mini TL
    >> lamp. Two pins on each end.
    >>
    >> Looking at Philips technical site I see that the recommended ballast for
    >> this kind of Philips lamp/lamp would be type BPL 02W. This ballast is a
    >> simple inductor. It's compactish, 85mm x 39mm x 28mm. Wiring is standard
    >> when using a choke and a starter.
    >>
    >> But, the electronic ballast in this luminaire does not employ the
    >> heaters.
    >> Pins at both end are joined together.

    >
    > Many of those cheap battery inverters don't drive the tube
    > very well. The lack of preheating will result in fewer starts,
    > but worse, they often significantly under-run the tube, meaning
    > the filaments don't get as hot as they should, ant this also
    > reduces tube live. Often doesn't matter with battery lights as
    > they aren't operated for that long (battery replacement price
    > and frequency would become a significant issue).
    >
    >> I suppose that whether employing the cheap electronic ballast or the
    >> choke,
    >> the lamp gives the same light output. True? But for economy, I guess one

    >
    > As I said, many of those cheap battery inverters significantly
    > under-run the tube, and get short tube life as a result.
    >
    >> would always go with the proprietry electronic ballast. Although mains
    >> working would require a step doen transformer. So, cost savings would
    >> not materilise - perhaps.
    >>
    >> Not sure about any differences in lamp protection and safety.
    >>
    >> I just get to wondering when I come across this kind of thing why anyone
    >> would select the choke ballast.

    >
    > They are cheap. It's also worth pointing out that the 4/6/8W T5
    > tubes don't work very well on 240V series ballasts with glow
    > starters. Two things are non-optimal - the 240V mains voltage
    > can sometimes instant-start them before the filaments get heated up,
    > but if it doesn't, it can take quite a bit of flashing to get them
    > started. Glow-start works well with all tubes from 24" upwards
    > on 240V, but not with the very short tubes.
    >
    > I would suggest you get a Philips MF-Matchbox 109 ballast. This
    > is a mains electronic ballast for this tube. It comes in two
    > types, Blue which is instant start, and Red which is preheat.
    > Preheat will give longer tube life in the case of frequently
    > switching on and off. Instant start may be preferable where
    > you don't want a second or so starting delay and either don't
    > switch on and off frequently or don't care about the reduction
    > in tube life. Both types require 4 connections to the tube and
    > power the filaments (unlike US instant-start circuits). Each
    > type is available in 2 shapes -- a matchbox, or a longer thinner
    > box (more suitable for going into a thin T5 fitting), and both
    > these are also available as just the bare circuit board too.
    >
    > RS do the Blue cased ones for around £7 (+ VAT/P&P):
    > http://uk.rs-online.com/web/search/...od=searchProducts&searchTerm=philips matchbox
    >
    > The other thing you might be interested in is making your own
    > ballast from an old CFL. There are some notes here:
    >
    > http://www.cucumber.demon.co.uk/lights/diy/
    >
    > The following shows the Philips matchbox ballast retrofitted
    > into a light and driving a 10W 2D lamp
    >
    > http://www.cucumber.demon.co.uk/lights/diy2/


    Lets say I'm making a table lamp using a miniature T5, something like an 8W
    or 13W lamp.

    There are at least two ways:

    1 You employ a 12V (say) adaptor, and that plugs into the table lamp. Of
    course the simple inverter inside the table lamp is very small and very
    cheap.

    2 Another way is to feed the lamp directly with AC mains using either
    something like a Philips Matchbox ballast, or a simple small choke ballast.

    Because I've got in my head the notion that option 2 is the more expensive
    option, because of expensive ballasts I'm always thinking that option 1 is
    better.

    But, I'm not sure option 2 needs to be as expensive as I think it is. I
    think this proves the point:

    http://www.dealec.co.uk/acatalog/erc_compact_fluorescent_ballasts_mec75.html
    Richard, Jul 27, 2008
    #6
  7. In article <>,
    "Richard" <> writes:
    >
    > Lets say I'm making a table lamp using a miniature T5, something like an 8W
    > or 13W lamp.
    >
    > There are at least two ways:
    >
    > 1 You employ a 12V (say) adaptor, and that plugs into the table lamp. Of
    > course the simple inverter inside the table lamp is very small and very
    > cheap.
    >
    > 2 Another way is to feed the lamp directly with AC mains using either
    > something like a Philips Matchbox ballast, or a simple small choke ballast.
    >
    > Because I've got in my head the notion that option 2 is the more expensive
    > option, because of expensive ballasts I'm always thinking that option 1 is
    > better.
    >
    > But, I'm not sure option 2 needs to be as expensive as I think it is. I
    > think this proves the point:
    >
    > http://www.dealec.co.uk/acatalog/erc_compact_fluorescent_ballasts_mec75.html


    You also need a glow starter and socket. Like I said, they don't
    work too well with the 4/6/8W tubes. You could try a wire-ended
    or plug-in electronic fluoractor based starter such as the
    Pulsestarter EFS 600. I've never tried one with the low power
    tubes, although the one I have here says 4W - 125W and it may
    work better than a glow starter.

    I would however go for the electronic ballast.

    --
    Andrew Gabriel
    [email address is not usable -- followup in the newsgroup]
    Andrew Gabriel, Jul 28, 2008
    #7
  8. Richard

    Richard Guest

    "Victor Roberts" <> wrote in message
    news:...
    > On Sun, 27 Jul 2008 13:35:40 +0100, "Richard"
    > <> wrote:
    >
    >>I bought a cheap flourescent luminair. Works of 12 VDC 500mA.
    >>
    >>I took it apart because I thought the lamp inside is about the right size
    >>for a project. Ballast is electronic on a small PCB, only a few descrete
    >>components. Obviously the ballast is cheap to make.
    >>
    >>Inside is an unbranded T5 lamp of 8W. It's 288mm long so it is a mini TL
    >>lamp. Two pins on each end.
    >>
    >>Looking at Philips technical site I see that the recommended ballast for
    >>this kind of Philips lamp/lamp would be type BPL 02W. This ballast is a
    >>simple inductor. It's compactish, 85mm x 39mm x 28mm. Wiring is standard
    >>when using a choke and a starter.
    >>
    >>But, the electronic ballast in this luminaire does not employ the heaters.
    >>Pins at both end are joined together.

    >
    > Sorry to be a bit late to this discussion.
    >
    > As others have stated, the electronic ballast operates this
    > lamp in what we in the US would call instant start mode.
    >
    >>I suppose that whether employing the cheap electronic ballast or the
    >>choke,
    >>the lamp gives the same light output. True?

    >
    > Not true. Fluorescent lamps give more light output per watt
    > of power input when operated at frequencies above about
    > 10kHz. If the electronic ballast is of reasonable quality,
    > then it will give higher overall efficacy than the series
    > choke system.
    >
    >>But for economy, I guess one
    >>would always go with the proprietry electronic ballast. Although mains
    >>working would require a step doen transformer.

    >
    > No again. As I think Terry has pointed out, as long as the
    > mains have enough voltage, the series choke takes care of
    > the "excess" voltage.
    >
    >>So, cost savings would
    >>not materilise - perhaps.
    >>
    >>Not sure about any differences in lamp protection and safety.
    >>
    >>I just get to wondering when I come across this kind of thing why anyone
    >>would select the choke ballast.

    >
    > They were, and may still be, lower cost and that are also
    > the basic "standard" ballast for this type of lamp.
    >
    > --
    > Vic Roberts
    > http://www.RobertsResearchInc.com


    I think probably with a F8 T5 lamp, it's very often going to be used in a
    portable situation.

    In that context it's likely to be run of a 12V/24V DC supply. That means use
    of a small, inexpensive flourescent inverter.

    Some inveters may not drive the lamp fully. That's what I hear.

    Where the supply is 240v AC, the basic "standard" ballast is likely. Which
    can also be low cost.

    Just what I think I've picked up.
    Richard, Jul 31, 2008
    #8
  9. Richard

    icma Guest

    Can I use these circuits to drive the CCFL for PC illumination? They come
    with the inverters but they I'd like to mod so I can use 1 inverter for
    multiple bulbs. Thanks

    <> wrote in message
    news:Gz4jk.2612$...
    > Richard <> wrote:
    >> I bought a cheap flourescent luminair. Works of 12 VDC 500mA.

    >
    > There are some schematics for inverters designed to run small
    > fluorescent tubes off of low-voltage DC at
    > http://www.repairfaq.org/sam/samschem.htm#schamt
    > that you might find interesting.
    >
    > Matt Roberds
    >
    icma, Aug 20, 2008
    #9
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