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Re: [APD] LED Lighting

I found them to last when going for clsoer to 3v rather
than 3.5v. Of course my multimeter could be off that much,
but I don't think so.  Red LEDs don't seem to mind being
driven hard or even a tad overdriven. But the hybrids, they
seem to be touchier. At 4 volts they'd last a few days. At
3.5 they'd last sometimes for weeks, sometimes for months. 
At 3v, they seem to last period.

Chuck's advice about wallwarts if right on. Best to check
the voltage before loading and after putting a load on it.
You might be surprised at how far off they can be.

Scott H.
--- Chuck Gadd <cgadd at cfxc_com> wrote:
> Andy Lavery wrote:
> > The LEDs I've chosen to use have a Vf of 3.6v Vmax of
> 4.5, If 30mA peak 
> > 100mA - now call me crazy, but I was just going to use
> a good old 4.5v 
> > 1.6A wall wart to power it, running all the lights in
> parallel.
> They will probably pop!
> If you want them to last, don't run them too close to the
> Vmax.
> Also, most wall wart power supplies have very poor
> regulation.  On
> my led nightlight setup, I found that my 12vDC wall wart,
> it was
> actually putting out 18v!
> Under a higher current load, the output would probably
> drop, but
> the load from the LEDs wasn't enought to lower the
> voltage.
> If you want to avoid adding resistors and such, you could
> go with
> a power supply that puts out 8v, and put 2 leds in
> series.  Then each
> LED would get 4 volts, and they'd be happy.

S. Hieber

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