On Wednesday, 13 May 2020 12:47:09 UTC+1, AnthonyL wrote:

I have an old battery (6 x D cells) torch which has a fluorescent
tube, a spotlight and a flashing light behind a red (plastic) glass.

So THAT'S where it went. If you ever come round maybe you could bring it back


The torch also has a DC power input of unspecified voltage which then
runs into some circuitry.

same as the battery, 9v. Polarity matters for the fl tube, and probably for the flasher. You haven't just given it the wrong polarity?

1) The battery compartment has got corrosion, half of a spring has
gone (there are two springs at the bottom, one for each set of 3
batteries), but there is continuity between the spring connections. I
plan to take a spring off a defunct 6v lantern battery to replace the
damaged spring. What would be the best way to fix it?

Usually it's easiest to replace the whole piece of spring wire rather than splice partial bits. So however it's fixed on now. IME battery holder springs don't solder well. Some battery holders rivet the springs, and the rivets do solder.


2) The fluorescent tube is a Sylvania White F6W/W which has probably
been superseded. 210mm x 16mm. Grey/black at one end. Is there
anyway to test if this works outside of the torch?

close to 99% of fl tube failures are filament burnout. Check continuity between the 2 pins at each end. If either end is o/c it's a deadun - though there are ballasts that can get such tubes going.

3) I've put a 9v supply into the torch and at least the spotlight
functions though nothing else. All the connections appear to be
accessible. What should I be measuring for the fluorescent tube?

Whilst this is one of numerous "Covid" projects I have on the go are
modern LED torches a better bet?

Oh yes, much more efficient, longer lived, better efficacy, more reliable. But those old things are still cool. Before you shuffle this mortal coil they'll be collectible retro.

Though I don't like the light from
my head torch or even any that I've put into lamps

As Paul pointed out, cheapskate ballasts blacken & kill one end of the tube, so put it back in the other way round to increase its life.


NT