Flourescent unit starter-less?

sounds like a high-frequency electronic ballast, instead of the lump of iron type ...

Could it be a semi-resonant start fitting?

According to the wiki, high-frequency fittings didn't come in until the 90s.

only unleavened ore steam baked flourescents are starterless.

Yeast and sourdough need a starter.

There are 3 possible layouts:

1. externally accessible starter
2. built-in starter, not visible from outside
3. Electronic ballast with no starter.

30+ years old suggests 2 as the most likely. So I'd open that box & see if it has a starter wired directly in, or whether the ballast is electronic. After disconnecting power of course.

Bad connectors to the end of the tube can also cause flicker, though not commonly.

NT

An old fitting designed for a T10 that cannot start a new T8 as the mercury content is lower?

Was the lamp a like for like swap?

How many wires go to the plastic box? If it is a coil which would need a starter there may just be two. My electronic ballasts have atleast 6 wires, two for each end of the tube and two for the mains input. The electronic starters I bought a few years ago have worked well.

There are rapid start fluoros that do not use starters,some of the tubes for these have metallic paint strip along the full length some have earthed metal reflectors in close proximity to the tube

Time to dump it and go for LED. Or buy an LED tube for your fitting (most need no starter).

IIRC lack of grounding or a missing strip caused trouble starting, but no trouble once started.

NT

Its an electronic quickstart probably, and the whole unit will need to be changed. They seem to sort of lose their high strike voltage after a time, never unpotted on but they tend to start when working rather as if it was on a dimmer, but when they stop working they just flicker but a bit faster than the starter kind and without the little 'ting' noises. Brian

Well the ones in our old Studio wre 1980s and one went and needed just an electronic ballast fitting. Of course never managed to get a direct replacement but nothing a few self tapping screws could not sort out. N I know for a fact that you could get 12v small lights with electronic ballasts so I guess these were just more powerful ones, but of course on the mains you only need to generate the breakdown voltage but if the transformer inside has some shorted turns or the controlling device is leaky then the result is flickering. Have you thought of going down the led route? Brian

ISTR so called quick start ballasts. Not electronic, but no starter as such.

Phoned a large lighting retailer (Beacon Plymouth) and was told :- "tube blinking, the problem is with a) the tube, b) the starter or c) the choke". When I described the wired 9 x 1 x1" unit, he confirmed it was the choke and they have a lifetime of approx 4 replacement tubes or 15 years. So I can't complain after 30 years use. When I replace the whole unit, I'll put up a picture of the choke, in case someone Googles.

The LED equivalent of a 70w fluoro is 26w. Beacon sells a 6' unit for £39 but the tubes are not replaceable, it's a sealed unit, throw-away job.

Agreed, LCD is the way forwards but as the choke is a bit dodgy, I won't spend £24 on a separate LCD. The Deltech is also a sealed unit but at 35000 hours, should see me out :-

Heh, it could be anything including bad connections but choke failure is very low on likelihood.

Not IME

Aldi were doing 5' tubes much cheaper recently. They don't last forever. You can always improve LED life by dimming.

You should bypass the choke/ballast when fitting an LED tube anyway.

bit steep

so is that

A couple of weeks ago I was in uk.d-i-y posters loft (wave to Terry Casey) and found a fluorescent light with a starter but no choke. I think I took a photo. I would say that it was 30 years old.

That's a novelty. ;-) Bet the leccy board didn't like it.

Well it's still there and it still works.

The leccy board have no say on it.

yes

The only type of setup I can think of that uses a starter but no choke is the old resistor ballast lights.

NT

Actually "Quickstart"(tm). The technology is now over half a century old (predates 1972 at any rate). Essentially it's an autotransformer with tube heater taps at each end which is connected across the tube with a conventional magnetic ballast in series with the mains supply.

The ballast and transformer can be a combined high leakage transformer arrangement that does effectively the same function but I've only ever seen and used the separate ballast and transformer setup. There's no separate starter switch and the tube lights up in some 250 to 300ms after switch on with no flicker (about as fast as a 12v 35W halogen on a 60W rated electronic ballast "transformer").

The theory of operation is that the "Quickstart" transformer runs at close to full mains voltage delivering heater voltage (10 volts or so) which causes the thoriated filaments to reach full heat and emit a copious supply of electrons, allowing the tube to strike without the stress of positive ion cathode stripping bombardment to boost the filament to temperature. Once struck, the tube current drops the voltage down to just over 100vac, reducing the heater current voltage which continues to help run the filaments at a more optimal temperature than simply relying on tube current alone.

Tubes last far longer in luminaries fitted with the classic "Quickstart" circuit, especially when subjected to frequent switching cycles, typically lasting their full design life of 7 to 15 thousand hours to the

Unfortunately, the new mercury starved T8 tubes can't be started by this classic circuit so once your T12 tubes supply has been used up, you're looking to upgrading to an electronic ballast or else taking the pragmatic option of a retro-fit LED tube where you'd be well advised to remove the QS transformer at the very least if not the transformer and ballast itself.