LED bulb replacement for fluorescent tube puzzle

I would be inclined to move into the 21st century and buy a full on LED replacement unit

The one I have, one of the end pin pairs is a short circuit and the other is the 2 pins for L and N to supply the lamp. With that arrangement, putting it in a normal fitting results in a circuit through the ballast, the lamp at one end, the dummy starter (just a short) and the short at the other end back to neutral. It works whichever way round you put it in.

So, easy to wire from scratch, but I don't know what the effect of running direct from mains rather than via the old ballast would be. The LED will probably be taking less current than the fluorescent did, so the ballast would not be having so much effect anyway.

nib

All the re-wiring instructions I've seen say that the LED tube needs L+N to the pins at one end, so I'd gut everything else ...

Having spent a little time researching, this seems to be accurate...

By the time you have gutted the innards you will be left with an old fitting which if it’s been in a basement will probably be past its best. Mend it with a new fitting which is likely going to be more robust and low profile to boot.

Richard

The words on the ballast ("Choke and Starting Transformer"), "instant start", plus the addition of PFC capacitor suggest that probably counts as an electronic ballast

I would expect one has is the supply to the tube, and the other is just a bridge. So you could probably connect live to one pin on one end, neutral to one pin on the other, and then add a wire connecting to remaining pins on each end to each other. That way you would retain the ability to put the tube in either way round without risking tripping the circuit by connecting the "straight through" pins to the switched supply.

\i wouldn't argue with that...

This. I did a bit of web searching and had my meter and discovered that one I end is a straight short and the other has a high resistance. But after gutting and rewiring it still wouldn’t work and I thingkthe problem with the old one was less to do with the tube/ballast but with the spring clips at the end which are very loose.

I’ll just replace the whole thing next week! That’ll teach me for going for the “easy option”. ;-)

Tim

Depends, those in my garage and shed are long discontinued screwfix models, polycarbonate shell and clip-on diffuser, keeps the crud and creepy-crawlies out, still good as new ...

You can probably buy replacement 'tomstones' but if you're past the point where it's good money after bad ...

Tim’s photo shows a bog standard rectangular channel to contain the ballast and wiring as typical of domestic flourecents the diffuser is probably cheap plastic held in place by end plates. I do not think his compare to yours so not worth keeping in my opinion.