What's this electronic component? Non boaty...

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DavidGrieves

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Hi

Can anybody identify this component? Non boaty question but there must be a few electronic experts out there.

It's on a pcb for a small portable fluorescent work lamp. It's about 4mm diameter and about 15mm long. It is the first component soldered in the 240v live side of the circuit.
The glass has cracked. When I push the component together(with insulated tools) the lamp comes on. Looks like a small glass fuse. Where can I buy one?

Thanks

David

Sorry, photo didn't work first time
 
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Picture would be best but in the absence of a picture, does it have any writing on it? Since it's a portable lamp, I would expect there to be a charging circuit which I would expect to start with a rectifier stage which in turn suggests that it could be a diode, a guess which is supported by an observation that many diodes do look like glass tubes. Does it have a line or some other marking on one end only? Of course, are you sure it is not a fuse?

To answer your question - you can (most likely) buy it from Maplins or RS Components
 
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It could be a fuse. Get a magnifying glass on it. You may be able to see markings/letters on it.
At 4mm dia x 15mm length it seems a bit big to be a glass encapsulated diode.
 
Looks like a reed switch (a switch activated by a magnet) is there anything that would activate it. Just seen your last post it would seem to be a fuse its going to be quite low if there is a wattage on the unit divide that by the input voltage which will give you the current in amps therefore the fuse size.
 
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Seeing the picture and reading the description is FU, and no indication of it having polarity, it appears to be a fuse. It appears to be before the rectifier diodes ie the black things behind it, so again suggests a fuse. Does it have a single, consistently thin piece of wire running through it? Either way, best bet is to go to Maplins and ask for "one of these".

I would not rate the fuse by the 8W light output, it would be the rate at which the batteries can/will charge which should be higher. If they confirm it is a fuse, connect an ammeter in its place and measure the current when the battery is charging normally, add 50% or so for buffer and find the nearest fuse they can provide that will fit.
 
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EugeneR said:
Seeing the picture and reading the description is FU, and no indication of it having polarity, it appears to be a fuse. It appears to be before the rectifier diodes ie the black things behind it, so again suggests a fuse. Does it have a single, consistently thin piece of wire running through it? Either way, best bet is to go to Maplins and ask for "one of these".

I would not rate the fuse by the 8W light output, it would be the rate at which the batteries can/will charge which should be higher. If they confirm it is a fuse, connect an ammeter in its place and measure the current when the battery is charging normally, add 50% or so for buffer and find the nearest fuse they can provide that will fit.
Click to expand...

I'm not sure that a battery is involved; OP hasn't said and it may simply be on a trailing lead. In any event I would caution against trying to measure the current without first checking that the DVM can measure current at 240v AC. Not all meters can measure AC and it would be a pity to fry it for want of checking beforehand.

Maplins don't do the solder in fuses. I've tried in the past so, if I were OP, I would order one of these http://www.ebay.co.uk/itm/Axial-Lea...Supplies_ET&hash=item1c1e60ae41#ht_1448wt_798
If that is too small then he could go up a size to 250mA
 
Fuses are not usually gas tight like that, they are generally simple tubes with end caps. That looks more like some sort of light bulb, maybe a neon indicator.
 
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