On 29 abr, 19:33, "Phil Allison" wrote:
"Father Haskell"

Flicker frequency? *CFLs flicker in the kHz range. *Imperceptable.

** The light of a CFL is modulated at 100 Hz too.

Cos the internal DC supply is very poorly filtered.

In general, the 100Hz ( or 120Hz) light modulation is less than experienced
with regular fluoros and low wattage ( 60 or 70 W) incandescent lamps.

.... *Phil

That is also true. Specially in cheap (read: bad quality) CFL´s. The
effect becomes worse as the CFL ages, I guess that happens because the
poor quality filter caps inside the ballast lose capacitance as the
heat generated by the electronics cooks them.

Inside brand CFL´s I have found 105ºC caps inside, cheap ones usually
have 85ºC caps and with less capacitance. In some CFL´s the internal
fuse opens when one of the filter capacitors fail shorted, often after
venting, in some others the filter capacitor just opens electrically
and the CFL starts to flicker badly at 120 Hz. That also happens with
cheap chinese ballasts for linear fluorescent tubes.

One more reason to avoid *no name* CFL´s.