supply fault?

[fireman22]

hi guys, my mate just phoned me, while on his computer the light in his room went really bright so much that he said he ducked. his parnter shouted to him, what was he doing with the lights? he says the other electrical equipment is all ok his computer wasnt affected nor was corrie.
he did say the lamp in the table lamp went bright too. i said it seems like a supply problem as not just lighting circuit as socket feeding table lamp was also affected. all bulbs are normal incandescent, any ideas. i said we will probably have to ask to have a tester put on mains supply.

 

[RF Lighting]

Does sound like overvoltage.

Might just be a breif fault on the supply network.

If it happens again, I'd start to get worried.

 

[securespark]

Did he knock the lamp?

Whenever I do, the light increases noticibly, but on switching off & on again, the lamp fails.

 

[fireman22]

no all the lights ceiling etc went really bright including the table lamp then went back to normal brightness.

 

[plugwash]

One thing to note is that the human eye is very sensitive to rapid changes in light intensity. Combine this with the fact that the light output of incandescent lamps increases with more than the cube of the voltage and people often notice fluctuations in lighting that aren't a problem for most equipment.