CFLs

[linuxguru]

I took a look at the electronics in the base of a generic, el-cheapo Compact-Fluorescent Lamp (CFL) after it died. Sure enough, there was a burst electrolytic in there - 2.2uF, 250v - one of two caps in series after the mains bridge rectifier. The circuit is a minimal self-oscillating half-bridge topology, with transformer-driven base drive to two 13001 bipolar transistors - very similar to most PC PSUs, except that instead of a load transformer there's just an inductor, blocking capacitor and the two CFL filament loads, forming a series-resonant load.

I replaced the two primary 2.2uF, 250v no-name caps with Sam-young SXE (I know it's crap, but it's better crap than what it replaced) and the lamp came back to life immediately. It appears that the limiting components w.r.t endurance in el-cheapo CFLs are the electrolytics - replace the electrolytics with 105c non-aqueous types, and it's entirely possible that the driver electronics will outlive the CFL tube.

[kc8adu]

Re: CFLs

i wound up with 100+thinlite ballasts that had complaints of flicker.a major rv mfr i fix stuff for gave them to me for parts.
on each and every one was a 1000mfd 35v axial lytic that was open.it was a weird name i had never seen before.like chen hong or such.
fixed all of them.
us solar users like free 12v dc stuff!