[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [APD] LED Technology (again)
I know lots of folks that complained about the flicker of fluorescents. Simple magnetic ballast lamps turn on and off 120 times per second -- once for each half of the main's current cycle of 60 Hz (common in the USA or 100 times for for the 50 Hz common in Europe). However, compact flourescents, on electronic ballasts, which use an inverter to increase the cycles per second, cycling is anywhere between 13,000 to 45,000 times per second, depending on the particular ballast circuit. If the flicker associated with *those* frequencies was perceptible and therefore bothersome, those folks would have a much harder time ever watching television or movies. Television (at least CRT units) cycle at 120 times per second-- film movies shown through a projector "blink" at about the same rate -- Hollywood films, typicially shot at 24 frames per seceond to save film, usually have three shutter swipes per frame to yield 72 "blinks" per second. Both of those rates are
substantialy less than the rates for compact fluorescents. Sometimes what people think bothers them is really just their own thinking.
However, I've yet to see fluorescent lighting that makes objects appear in color indistinguishable from their appearance under the excessviely red light of standard incandescent bulbs. Most ofthe "warm white" bulbs available have strong yellow spikes compared to "cool" bulbs rather than added red -- a noticeable difference if doing A-B tests of the bulbs. Sometimes we miss that to which we are most used.
Perhaps oddest of all is the unatural excess stauration of yellow light on the TV show CSI Miami. Everyone on the show looks jaundiced, but the show apparantly is a hit with lots of folks anyway, despite the 120 binks per second and apparently pandemic liver problems.
* * * *
show up, show off,
There are still a few weeks left to enter The AGA 8th Annual International Aquascaping Contest.
Entries can be made until September 30, 2007
Info is at
----- Original Message ----
From: Jerry Baker <jerry at bakerweb_biz>
To: aquatic plants digest <aquatic-plants at actwin_com>
Sent: Tuesday, September 11, 2007 4:52:29 AM
Subject: Re: [APD] LED Technology (again)
Chris Hotte wrote:
> Same wife factor here has been noted with simple CF white light screw in
> types. She would not accept the ones in the hallway where there is a
> dressing mirror. The complaints did not diminish after a 1 month trial
> period. She could not stand to look at herself under "white" CF light.
The warm white CF bulbs are indistinguishable from incandescent lights.
For some people. just knowing they are there bothers them.
Aquatic-Plants mailing list
Aquatic-Plants at actwin_com