31 Oct
2011
31 Oct
'11
9:42 a.m.
On Oct 31, 2011, at 12:29 PM, Chuck Guzis wrote:
On 31 Oct 2011 at 9:47, David Riley wrote:
I've noticed the same thing. Again, a few cents would get them the proper
rectification, as you described, but given that they probably spend only a few bucks on
producing the strings, it would eat into someone's profits in China.
It's very distracting and irritating, and I
doubt the lower frequency
saved them more than a few cents per $30,000 car in drive electronics.
We're approaching the time of year when my field of vision is
polluted with those damned flickering LED outdoor Christmas tree
light displays. I must have some sort of visual impairment because I
can pick out the flicker from a mile away--literally. It reminds me
of a nest of ants crawling all over the display. Moral: Even a 60Hz multiplex rate is too slow for
some people's
vision.
60Hz refresh always gave me headaches with computer monitors, but never with TVs. I
suspect it may be because the phosphors on computer monitors decayed faster (in order to
ghost less, I suppose?), but an LED decays nearly instantaneously. That's why you
have to get the PWM frequency up in at least the hundreds of Hz, because the rods and
cones in your eyeball pick up the change fairly quickly.
Of course, it does seem to be up to individual anatomy, much like with televisions; my
father swears he can't tell the difference between an old NTSC TV and 1080p, but I
think he's just being contrary. :-)
- Dave