Obsolete fluorescent light fittings

[cmjones01]

Originally Posted by Zelandeth

Cmjones01: Doubt this is the same thing then - the Netaline looks to be rather more substantial bit of kit than that - and as far as I'm aware there weren't any twin tube versions.

That is cute! Make your kitchen look like a 1950s factory floor in one easy step. I love the styling!

[raditechman]

Kalee20 said:
..."I can't see that somehow - fluorescent lamps need AC to work."...
They can, did and will work on DC mains, using a resistance ballast. As long as the mains voltage was high enough to strike up the lamps initial discharge. They were not commonly used on DC mains as they were inefficient due to the waste energy in the resistance, also you had to swap the tube ends around often, this meant removing the tube and refitting it with the opposite ends swapped around. On some circuits a switch was provided to do this. If this was not done mercury would accumulate at one end of the tube. Of course it is many years since the UK had DC mains.
John

[julie_m]

Some years ago I remember an alert being issued about some imported car inspection lamps which contained a (short) fluorescent tube and used a long, resistive power lead as a ballast.

They worked fine until you shortened the lead .....

[bobsterkent]

the mazda netaline advert on You Tube

[AndiiT]

Originally Posted by AC/HL

.....The choke is there to provide the kick to strike the tube and then the impedance to prevent self destruction. Did they have different tubes, or is the "kick" not necessary?

Hi,
The tube was a standard four foot one, nothing fancy.
I may as well own up here and mention that at some point towards the end of the fittings life I decided to attempt rewiring it, not realizing that the wire was resistance wire, and learned how to "kill" a fluorescent tube in one fowl swoop!

Originally Posted by AC/HL

Back then we also had a very space age thing in our house, a circular fluorescent light, remember them?

I certainly remeber the circular fittings, at one time I think that every other house in our village had one fitted in the living room!

Andrew

[russell_w_b]

Originally Posted by raditechman

Kalee20 said:
..."I can't see that somehow - fluorescent lamps need AC to work."...
They can, did and will work on DC mains, using a resistance ballast. .

Didn't ships on d.c. supplies have light-switches that reversed the polarity to the fluorescent fitting each time the lamp was switched on?

Seem to remember being told this by some old sea-dog or other...

[kalee20]

Well there's a thing!

Did the cathode need a heating supply for use on DC mains (as I suggested in my earlier post), or did it keep hot due to positive ion bombardment à la OZ4 rectifier?

How did life compare with AC drive (assuming the polarity reversals took place)?

This is interesting!

[russell_w_b]

Originally Posted by kalee20

Well there's a thing!

Did the cathode need a heating supply for use on DC mains (as I suggested in my earlier post), or did it keep hot due to positive ion bombardment à la OZ4 rectifier?

Nothing mentioned about heating on d.c. supplies in the 1954 Eleectrical Engineers' Reference Book (Newnes), but it says the following:

* Fluorescent lamps may be operated on d.c. supplies, but the practice is not recommended unless there is special reason for doing so.

* The choke must be retained for the starting 'kick', and a series resistance must be used to limit current (80W lamp on 200V d.c. - 116 Ohms; 230V d.c. - 147 Ohms; 250V d.c. - 172 Ohms. 205 Ohms, 290 Ohms and 350 Ohms respectively for a 40W lamp).

* The starter switch operation may become uncertain under 230V d.c., and a hand-operated switch may have to be substituted. When glow-type starters are used, two of opposite polarity are used in parallel to ensure a glow will strike in one of them.

* A polarity reversal switch should be fitted to the cct as a whole (as I mentioned in my 'sea-dog' post) to correct for 'dark-end' effect.

* No PF capacitor is, of course, necessary.

[chipp1968]

Certainly ships like the Queen Mary and Elizabeth were full of hidden fluorescent lights , sited behind cornicing and decorative ceiling lights and panels.

[cmjones01]

I can certainly remember seeing fluorescent tubes on the London Underground which were dark at one end. This would have been in the early 1980s. The explanation proffered by my dad was that they were likely to be powered from DC, since there's a lot of it about on the Underground.

[Brian R Pateman]

Unfortunately your Dad was wrong.

The fluorescent lights on LU are powered from good old fashioned AC mains. I have been responsible for the installation of many of them.

[ppppenguin]

Originally Posted by Brian R Pateman

The fluorescent lights on LU are powered from good old fashioned AC mains. I have been responsible for the installation of many of them.

In the stations yes but surely not the ones on the trains. Though trains used ordinary incandescent lamps for many years before fluoresecents were introduced.

[McMurdo]

Was horrible. Like a milk bottle

Probably a Philips SL, available 1980 onwards

http://americanhistory.si.edu/lighti...GES/phil1b.jpg

[Herald1360]

Originally Posted by ppppenguin

In the stations yes but surely not the ones on the trains. Though trains used ordinary incandescent lamps for many years before fluoresecents were introduced.

Didn't they wait for inverter technology before fluorescents were introduced in rolling stock? So AC anyway, just H'er F.

[Zelandeth]

Like a milk bottle you say...Hmm...sounds like one of the early SL series.

The SL*1000 McMurdo has a picture of there was the prototype version of what we saw commercially as the SL*18 (and slightly later, the SL*25).

Below is a picture of one from 1983.

http://loz.zelandeth.org/lamps/cf/ph...18/profile.jpg

I've a page about the SL*18 Here which might be of interest.

There has been talk about an inverter based CFL called the U-Lite by a company called Interlectric which MAY have pre-dated the SL series - however this is a claim which seems to float around periodically - and aside from one fuzzy scan of an advert I've never seen any evidence of its existence.

I spent quite a long time trying to track down an SL*18 for my collection - then overnight ended up with two of them and a 25 as well. There were so called "comfort" versions produced from the late 80s which had a white housing and an opal diffuser as well - technologically the same lamp though.

[McMurdo]

I've seen plenty still working, a local pub here has 2 on top of the gate pillars.
RS sold them at one time

[Hunts smoothing bomb]

Wow! this is a cool thread, I too love old lighting and lamps.

I have admired (if that is the right word) a florry fitting in my aunts shed for about 23 years. It is made by ATLAS and is a light brown colour and the tube sticks out of the housing naked, the end cap is connected on a piece of wire, the other end goes into kind of cowl and has holes in it where you can see a light bulb, or so I thought until I read this, it is infact the four pinned starter lamp!

It always intrigued me and still does as when you turn it on, the starter lamp glows brightly and each time the tube flickers the lamp dips until the tube stays lit and then the starter lamp glows just a dull yellow.

I don't suppose anyone could send me a couple of those BC end cap converters could they? I'd love to have a vintage looking light in my workshop at the new house when I build it

Surprised Tas (Tazman1966) hasn't commented on here as I know he likes vintage lamps too.

Cheers

[Lucien Nunes]

Surely fluo lighting on underground stock was always powered from a rotary converter? Can't see how they would have sensibly made it run direct from traction current at 600 / 630V DC.

[Tazman1966]

Originally Posted by Hunts smoothing bomb

...Wow! this is a cool thread, I too love old lighting and lamps...

I agree and have been reading and digesting intently.

Originally Posted by Hunts smoothing bomb

...Surprised Tas (Tazman1966) hasn't commented on here as I know he likes vintage lamps too...

Too true - just so much to read and absorb first...

[Framer Dave]

Regarding DC operation of flourescents. In the late 60s I worked at a paper mill where power was generated by a steam turbine driving a large dynamo through a gearbox. Individual machines throughout the mill were driven by DC motors. A very small amount of AC was available via a rotary converter for the offices etc.

In my department - the Salle, or paper inspection room - there were about 80 twin tube 80W fittings. These were standard fittings with an additional box on the top, presumably containing a ballast resistor. They ran on DC and over a period of time could be seen to darken towards one end. About four times a year the mill electrician would reverse the connections to the entire installation.

Earlier I worked in an engineering factory which also had a substantial DC supply. I think this may have been quite common at the time.

Regards,