Why can't you use energy saving light bulbs with dimmer switches or timers?

Question

On the back of energy saving light bulb boxes it always says that they can't be used with dimmers switches, PIR or timer switches, why?

Surely it would make more sense to use a timer at home with a lamp that is better for the environment!!

Answer 1

Energy saving light bulbs use the same technology as fluorescent tubes, with a built in starter.

These types of bulbs need to take a lot of inrush (startup) current, and then take a very small amount of current after it has lit. This huge inrush current is a lot higher than cheaper, more commonly available dimmer switches can handle. Microprocessor controlled dimmer switches that can handle this current are becoming more prevalent but are about twice the price of a standard dimmer!

Answer 2

By energy saving bulbs I take it you mean fluroescent?
very simply speaking fluroescents are "regulated" as to power usage they use a specific amount of electric to produce light, drop that amount and they simply wont work at all.. which is why a dimmer wont work on them.. on an incandesent bulb (normal) you turn the electric supply down and the filiment just glows a little less and produces less light.

I do not however know why you couldnt use a timer on an energy saver, as timers are basicaly just a "switch" unless its some computer controled chip fed timer thats restricting the electric somehow. Or that the timers may not handle the initial surge of power(Fluros take quite a bit of power to "start").. but I wouldnt see that being a problem on a mechanical switch timer.. but possibly it might be on a electronic type...