On Dec 2, 3:47*pm, Larry Jaques wrote:
On Thu, 02 Dec 2010 14:10:40 -0500, Bill
wrote:

On 12/2/2010 8:23 AM, Larry Jaques wrote:
On Thu, 02 Dec 2010 02:02:06 -0500, *wrote:
I had to move a few bit to accommodate obstacles (like garage door
opener). *The luminaires with electronic ballasts featuring "instant
start" and less than 10% THD are about $40 each--lamps extra.

Total harmonic distortion in fluors? *New one on me.

Wikipedia says 1% THD is supposed to be inaudible to the human ear.
"Standard" (Lithonia) electronic ballasts are 20% THD
"Instant on and Rapid start" electronic ballast by Lithonia are 10% THD.

So they're saying that these babies HUM LIKE HELL, or what?
WTF is an audio distortion figure doing on a light fixture?!?


Don't get me started. THD is a useless spec. It 's like a single
number indicating impurities in ice cream. Some impurities are straw,
some are bat ****.

'Even order' harmonics are much easier to put up with than 'odd
order' (not related to the fundamental note) harmonics. (Please, all
you musicians and psycho-acousticians keep your shirts on, I know it
is an over simplification.)
Even order harmonics is how we tell instruments apart, odd order
is ..is.. like..Celine Dijon (without AutoTune.)