11 led circuit

I want to wire 11 20ma leds; parallel, series, or series parallel? Which is best?

www.cl.ais.net/farcir/ has a circular
circuit board that holds 11 leds for $4 that
will fit a flashlight. Look under miscellaneous.

Thanks.

Gordon

Supposedly that board includes locations for current limiting resistors, so I suspect that it is designed with all of the LEDs in parallel, but with each LED on a current limiting resistor.

My favorite configuration is a long series string of LEDs with a single current regulating device on the whole string. This forces the current to be the same in all of the LEDs, and allows you to use a single current regulator for all of the LEDs. The downside is that you need a higher voltage to supply the whole series string, which generally means some sort of boost converter, and if one device fails, the whole light goes out.

-Jon

Gordon, you might attract a little more interest in the Electronics/Battery Forum.
Moving........