Re: Broken touch sensitive lamp

[Calvin]

I've got a bed side lamp which, in normal operation, if I touch the base

> once it comes on, I touch it again it gets brighter, I touch it again it > gets brighter still, I touch it again and it turns off. Except now, after > changing the bulb, it is always on and at the brightest setting. Before I > cut the flex and put a switch in it can anyone suggest what the fault may be > and how it could be repaired? I could just sling it and buy another but it > is one of a matching pair so I would probably end up buying 2. > > TIA, > > Deryck

My guess is that it doesn't like the new bulb. What sort of bulb was in it before? Conventional or Enery Saving (CFL)? What wattage? What sort have you put in it now? As an experiment you could try a boring old conventional bulb just to check.

I've X-posted to uk.d-i-y as there are many posters there who might be able to help.

[Martin Crossley]

The triac probably went short-circuit if the old bulb blew. It is usually a metal-tabbed device such as a TIC226.

[Owain]

My guess is when the old bulb failed there was a current surge which blew the triac inside the dimmer circuit.

Owain

[jrwalliker]

I had one fail in exactly this way. The triac shorted as a result of the very high current which flowed when the bulb blew and arced internally with a bright flash and a pop. I looked up the data for the triac. It did not have a surge rating anywhere near high enough to survive this kind of fault, especially with the lamp close to the consumer unit (the lamp was in the hall in our case).

B&Q replaced the first one, but refused to replace the second which was just over a year old when the bulb blew. The manager insisted that nobody else had ever reported such a fault and anyway they were not obliged to replace goods more than 1 year old.

I made a token fuss in the shop, but it wasn't worth pursuing it further for =A312. I used a switch after that.

John

[The Medway Handyman]

Did his nose grow longer as he said it?

Bloody things are nothing but trouble.