Re: LEDs intensity solutions?

On Aug 5, 1:15 pm, "Vlad" <vladana...@xxxxxxxxx> wrote:
Does your voltage supply deviate very much from the 12V spec? Does the
voltage vary with time, as with a battery?

Regards,

Mark

Thanks Mark, I use wall adapter that give 12V/800mA... i got it for free,
but it said "For Information Technology Equipment use only", khm... is it
ok? Btw the adapter is not dead, broken or something.

Okay, since it's a fairly steady voltage, you don't need to worry
about voltage fluctuations changing the current. Also, power
consumption isn't really an issue either; for example the electrical
cost of sol.3 would cost about 1/4 cent (in the U.S.) per 10 hours of
operation.

I guess I'd go with sol.3, just because there are fewer parts to wire
together.

However, I would measure the actual voltages of the supply and diodes
under the expected current load (for sol.3, 160 mA total for the
supply, 20 mA each LED), and then use resistor values based on the
measured voltages.

For example, if the supply voltage were really 12.5 V, sol.3 would
produce 30 mA through each LED, not 20 mA.

Good luck,

Mark

.

Quantcast