Why cant you dim a fluorescent bulb?

[daniel_i_l]

Why can't you dim a fluorescent bulb?

 

[lpfr]

For a fluorescent tube to work, the filaments must stay hot enough to emit electrons and the gas hot enough to have a good pressure.

A fluorescent bulb is a fluorescent tube with an electronic circuit to feed and control the tube current.

A dimmer is an electronic circuit that control the how much time (in each half period) the charge is connected to the mains. It connects, say, two thirds of each half sinusoid to the charge.

This is incompatible with a tube without electronics, because the filaments will cool too much. This is also incompatible with the electronics of the bulb which has been conceived to be full time connected to the mains.