Fluorescent neon tube - how to vary light emission?

[lollobrigido]

varylight

I know I can't use a normal variator for bulb or alogen lamps, but is there somethig of similar for neon tubes?

thx
Lollo

 

[flatulent]

remove full cycles

One way is to disconnect it from the AC mains for one whole line cycle every N cycles. This will produce flicker.

If you drive the light with your own higher frequency oscillator, removing m out of n cycles will make the flicker frequency so high that the gas will continue to glow during the unpowered intervals and even if it went out and back on the human eye would not notice it.

Another custom driver method would be to use square waves and change the duty factor so that there would be zero volage between the positive and negative parts of the "square" wave that went from zero to 99% of the half period.

 

[maranaza]

dimming a fluorescent tube

Fluorescent tubes are usually dimmed by rising the ballast impedance. In electronic ballasts this is commonly achieved by increasing the operating frequency. You can find application notes and other info on the e.g. IR and Philips sites.

maranaza