21 Aug
2015
21 Aug
'15
3:57 p.m.
On 08/21/2015 08:36 AM, dwight wrote:
I was going to add something but it has already been
said several
times. I will add that if using a LED on an AC like signal of high
voltage, one should use a diode. I recommend using a shunt diode
rather than a series diode when high voltages are being dropped by
the resistor. It reduces the need for a high voltage diode but makes
the resistor hotter. Some red LEDs glow orange when not protected
from 12VAC. You can ask how I know. Dwight
Ever take a close look at a string of Christmas-tree LEDs? Most are
composed of a string of LEDs hooked directly across the AC line--no
rectifier diode to be found.
Some seek to reduce the 60Hz flicker by employing two strings to
illuminate on both half-cycles, reducing the flicker somewhat. Since
my eyes react to the flicker (it's like ants crawling over the string),
I found that simply employing a full-wave bridge rectifier can reduce
the appearance of flicker tremendously.
--Chuck