Bulb blew now dimmer switch wont work......

[ThatBloke0101]

....despite changing bulb the dimmer switch no longer dims the lights just switches on and off.
Now i have read elsewhere i need to replace the dimmer switch !!!

Surely i havent got to do this everytime a bulb blows ?
Obviously not so what is the problem ?

 

[Diyisfun]

You have just been unlucky

 

[holmslaw]

..

 

[bernardgreen]

when a filament lamp blows its just like a fuse blowing but the current can flow for longer than desired and damage the dimmer.

Worse than a fuse blowing. A fuse blowing does not increase the fault current due a fault elsewhere in the circuit. When a lamp blows it can become a near short circuit for a fraction of a second and take a lot more current than when lit normally.

Make sure you buy a good brand eg MK, crabtree, make sure it is suitable for your type of lighting and that it oversized for the load.

There are also lamps with fuses built in to prevent this happening.

Running a lamp dimmed, especially halogens, will reduce their life time.

 

[RossR]

Running a lamp dimmed, especially halogens, will reduce their life time.

That's debatable. It can increase the life.

 

[bernardgreen]

Running a lamp dimmed, especially halogens, will reduce their life time.

That's debatable. It can increase the life.

I agree the older filament lamps with inert gas did last longer when under run on a lower voltage sine wave supply. Chopped sine wave and pulse width modulated dimmers were known to cause some coiled filaments to vibrate more than they did on a sine wave supply thus leading to more mechanical ageing of the filament.

 

[ban-all-sheds]

How?

 

[RossR]

It's a complicated issue. Dimmers may increase or decrease halogen bulb life.


This is a better explanation than I could give: http://members.misty.com/don/bulb1.html

 

[radioredcat]

Also touch lamps suffer the same fate when the bulb blows.


Andy