On Fri, 07 Mar 2014 23:10:58 -0500, nospamgoingjag
wrote:

Jon, thanks for the info, I may pursue that for other lighting
opportunities.

Jasen, John Field has straightened me out on my overbly ambitious
requirements.

John, thanks for the further feedback. I obviously need to revisit
the LED count and layout before pursuing further.

---
Oops...

Earlier I assumed that the 3528 has three LEDs in the same package,
like a 5050, but it doesn't.

It has a single LED per package with specs similar to each of the
LEDs in the 5050.

That is, a forward voltage of 3.2V typical, with a forward current
of 20mA through the LED.

For 6 parallel strings of nine 5050s with 3 series-connected LEDs
and one dropping resistor per 5050, that's 20mA per 5050 times 9
5050s per string times six strings, which equals about 1080
milliamperes with 12VDC across the array.

Since the 3528s only have one LED per package, six strings of 12
LEDs would be 72 LEDs, and wiring them up as 6 parallel strings of 4
parallel groups of 3 series-connected LEDS with their
current-limiting resistors would result in 20mA per group times 4
groups per string times 6 strings, which equals 480mA with 12V
across the array.

John Fields