In article , Mark Lloyd wrote:
On Thu, 07 Dec 2006 20:27:11 GMT, Art Todesco
wrote:

Mark Lloyd wrote:
On Thu, 07 Dec 2006 08:56:45 -0600, Jim Rusling
wrote:

"Joseph Meehan" wrote:

The 35-LED strings probably have internal fullwave rectifiers.
I wish they did have full wave rectifiers.

SOME strings have them. The first 35-LED string I bought didn't and
used one polarity only (actually lit less than half the time).

The ones I bought last year didn't and all I have seen in the store
didn't either. You can tell because they "flicker" quite a bit.

60Hz flicker is supposed to be too fast to be visible. Some people see
faster than others.
I have added full wave rectifiers to the ones I have. They get
brighter ..... yes I realize that could shorten the life. But, they
flicker less and look a whole lot better.

The 120Hz you get by adding the rectifier will be brighter (if you get
the polarity right). The LEDs will PROBABLY be able to handle the
higher duty cycle. There should be little or no effect on lifetime
since you're not increasing the maximum current (actually decreasing
it a little because of the 1.4V drop across 2 diode junctions) and the
LEDs aren't generating much heat.

I would not count on that! I have seen a lot of LED products where the
LEDs are being run rather aggressively, close to or even in excess of the
ratings of the LEDs or usual ratings for such size LEDs.

At your own risk!

- Don Klipstein )