On 14/05/2020 12:41, AnthonyL wrote:
On Wed, 13 May 2020 13:17:15 -0700 (PDT), wrote:

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?



At this stage I don't know, I've assume centre = +ve but there is no
indication on the socket. As also I'm assuming 9v because that is 6 x
"D" at 1.5v ea.

I guess I'll lose nothing if the fluorescent tube isn't in by rigging
up a reverse polarity connection or clip a PP3 in where the 'D' cells
go and see which way round things are at a bulb.

A filament bulb won't care at all which way round the battery is but the
inverter for the fluoro tube will probably emit its magic smoke if you
connect the battery the wrong way around.

Usually you can work out the polarity in the end with the conical coiled
spring is negative and the end with the small rigid centre is positive.

These days it might be altogether simpler to buy a modern power LED
torch and throw the old thing away. It might even be cheaper than buying
a replacement mini fluoro tube. It will almost certainly be brighter.


--
Regards,
Martin Brown