How do power a series of Luxeon LEDs given an AC power source?

Question

I want to make a lamp using Luxeon LEDs, up to 50 of them, and I want it to plug in to an AC power outlet. Converting to DC is acceptable of course but I am not sure where to get started on driving these little buggers.

Answer 1

"I suspect you would just need the correct resistor(s) to giveyou the right voltage" isn't correct.

A series resistor sets the current through the diode/s.

An l.e.d. is a current, not voltage, operated device. You design to pass a desired current throught them.

To run them from an a.c. source the source first has to be rectified. A bridge rectifier will do this - it must have a high enough voltage rating. Smoothing/filtering/regulation is not strictly necessary.

The sum of the forward voltages for the number of l.e.ds you want to use in series (which depends on their type) must be below the value of d.c you want to use. You may connect additional l.e.ds in series in a separate parallel string, each string will need its own current-setting resistor.

This may help http://www.davidbridgen.com/leds.htm

Answer 2

I charge batteries by using the AC power from the 120V outlet, to a step-down tranformer, to a bridge rectifier. The DC can be cleaned up at this point. The DC goes thru various combinations of resistors to get he charging amperage I need. I suspect you would just need the correct resistor(s) to giveyou the right voltage.

Answer 3

the way that's finished in industry is to apply strings of 5, 10, or 15 etc LEDs in sequence and then placed the strings in parallel and then tension the full bunch from a switching skill grant, which removes the loss interior the resistor. this form if an LED fails open, in user-friendly terms that one string is going dark and something shop working. With a switching skill grant, very almost any voltage skill source might properly be accomodated. bigger voltages have the finished factor approximately smaller cord for the gadget. once you're saying "in one report" it is complicated to comprehend what you advise.

Answer 4

Get start by searching for a simple AC -> Dc converter. Making the circuit is pretty simple, you only need a few diodes, op-amps and concrete components.