Re: ELECTRONIC BALLAST?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Matthew Smith" <matt-at-kbc-dot-net.au> 

Ed Phillips wrote:
>Anyone have a clue as to the circuit of the ballast/power supplies for
>screw-in  fluorescent lamps?  Just cut a dead one apart and found more
>stuff than I expected.  Six diodes, 2 HV transistors, one diac, one PTC
>resistor, two inductors (one closed ferrite core with fairly heavy
>wire), two 22 ufd, 200V electrolytics and miscellaneous other resistors
>and capacitors.  A lot more stuff than I expected and that probably
>explains the RF interference they generate.

There's some stuff at Repair 
FAQ:<http://repairfaq.ece.drexel.edu/sam/flamp.htm#fb3> - includes bits on 
electronic ballasts.

Schematics at:
<http://repairfaq.ece.drexel.edu/sam/samschem.htm#schcfl1>

Some (can't speak for all) 240V ac models may be run off 300V dc - first 
stage in the one I had apart is just a bridge rectifier.

Cheers

M

-- 
Matthew Smith
Kadina Business Consultancy
South Australia