Problem with illuminated ring magnifier

[ppppenguin]

I've been given a rather nice illuminated magnifier. It uses a circular tube like this: http://www.maplin.co.uk/p/22w-circular-f...tube-ap90x plus a conventional starter and ballast. The latter are contained in a box at the base of the lamp.

It doesn't work. The starter flashes away merrily making lots of RFI. The tube has continuity on both heaters and has no blackening. Not a peep out of the tube. Can't even see heaters glowing or any flashing. Tried a repalcement starter with no joy. I suppose I could get a replacement tube but they are not availble very widely.

Any ideas?

I also wonder if these tubes will work with an electtronic ballast for a nicer light. Or wind some LED tape round and round where the tube is.

[Refugee]

I have got one of those that has suffered Mazak plague in its base. It still worked when I last tested it about 10 years ago when I bought a Maplin one.

[Yorkie]

I'm sure you know this Jeffrey, but I'll mention it anyway just in case. The instructions for switching on these lamps tell you to press and hold the 'on' button for a couple of seconds, then let go.

I've got one of these circular fluorescent lamps and if I don't do that on mine, it won't start.

You'd think that switching on a lamp was so simple that you don't need to read instructions - leastways, that's how I saw it!

(Not saying that's the problem with yours of course, but it might be worth a try).

[ppppenguin]

Mine is a nice solid one made by Allen. Looks like this except it has a clamp rather than a heavy base.

I wonder if the choke has had it. I may have a suitably rated one in the junk box but I doubt it. It's an ordinary Tridonic EC22/30. There's a faint air of cooked coil hanging around but no discolouring. I could stick it on an inductance bridge but have no idea what to expect. Any other suggestions for teting it? I suppose I could do a ring test, like you would do on a LOPT.

If I needs replacing and there isn't one in the junkbox I'm going electronic to avoid the flicker. Or use LEDs as I suggested above. I wonder how much LED I would need to give the same or more light output. The obvious answer is about 10 to 15 watts of them but that's not entirely helpful.

[Radio Fixer]

I could find my notebook and it will tell me what my chokes  were for L if you like.

However, I recommend going electronic.  Bought my ballast off the Web and Tube 8" at 22W.  Sorry didn't keep where I got them from Ugh!! (Bought two of each though)

My tubes didn't last for long as I think the choke ballast was intended for a higher wattage tube and had flicker but cured now. Instant start as well.

   

PS: just looked in the notebook and my lamp had 3 chokes in series of 0.44H and 16 Ohms each.

Gary