LED Lighting Help Please

[Smarsh]

Hey
Im using some PCB's with LED's attached as lighting.
The boards have 8 channel in parallel. Each channel has 3 LED's in series.
All the channel inputs have been shorted, so that all channels receive the same voltage.
4 of the channels have red LED's in series, which require a voltage of 2.1 V per LED. I have used a 200 OHM resistor to reduce the voltage to 6V.
The other channels have white LEDS, which are at the required 9 V.
The current power supply Im using is a regulated 9V DC with a max current of 2.5A.

I was wondering if I then wire multiple separate boards in parallel how I calculate how large of a power supply I need? Currently I have 7 boards in parallel, which are a bit dull. Ideally I would like to wire up 15. So if anyone could help point me in the right direction that would be appreciated.
Thanks

 

[crutschow]

You add together all the various currents. Since you haven't said what all of them are I can't help you with the calculation.

If you are operating the white LEDs without any series resistance, that's a no-no. All LEDs require some resistance in series to stabilize the LED current value.