Robust Stardust
07-08-2015, 11:03 PM
Hello saber fanatics!
11592
(Please see here for a MUCH higher resolution upload (http://www.binarysunsetdesign.files.wordpress.com/2015/07/robust-stardust-pcv3-5_cex-wiring-diagram-v1-0.jpg) of the diagram)
I have completed the first draft of my wiring diagram for the PCv3.5 + Color Extender, and would love to hear comments and suggestions from the pros! A lot of hours were spent reading over the amazing manual that Erv wrote and the many helpful posts on these forums. How does it look? Everything is pretty by-the-book (or so I hope). My only major question is if I'm wiring up the crystal chamber LEDs correctly. I'm using three separate LEDs instead of a common cathode, but I'm wiring them with a common ground to the accent LED ground pad, basically making a DIY common cathode RGB LED (kinda-sorta). Is this okay, electronically speaking? And don't worry, I have plans for making the RGB LEDs diffuse and blend together to evenly illuminate the crystal.
Also, I'm assuming that all the PWM control signals for color channels 1, 2, and 3 are all 3.3V, and at a max current of 18mA. Correct?
The LEDs for the crystal chamber that I'm using are all rated for 20mA max, but I'm choosing to run them all at 15 mA (or 0.015 amps) just to be safe.
Red forward voltage (Vf) = 2.0
Blue Vf =3.0
Green Vf =3.0
My resistor calculations for the crystal chamber LEDs using Ohm's Law are as follows:
Red: 100 Ohm, 1/8 watt resistor
R = (3.3-2.0)/0.015 = 86.66 Ohms, so round up to 100 Ohms?
P = 86.66 x (0.015)2 = 0.01949 watts, so round up to 0.125 or 1/8 watt?
Blue: 20 Ohm, 1/8 watt resistor
R = (3.3-3.0)/0.015 = 20 Ohms, no rounding?
P = 20 x (0.015)2 = 0.0045 watts, so round up to 0.125 or 1/8 watt?
Green: 20 Ohm, 1/8 watt resistor (same Vf and current as the blue die)
R = (3.3-3.0)/0.015 = 20 Ohms, no rounding?
P = 20 x (0.015)2 = 0.0045 watts, so round up to 0.125 or 1/8 watt?
I've been wondering where the best electronic supply place is to find these small wattage resistors, as they aren't carried here at TCSS.... perhaps Mouser?
Thanks in advance for your comments and suggestions! :D
11592
(Please see here for a MUCH higher resolution upload (http://www.binarysunsetdesign.files.wordpress.com/2015/07/robust-stardust-pcv3-5_cex-wiring-diagram-v1-0.jpg) of the diagram)
I have completed the first draft of my wiring diagram for the PCv3.5 + Color Extender, and would love to hear comments and suggestions from the pros! A lot of hours were spent reading over the amazing manual that Erv wrote and the many helpful posts on these forums. How does it look? Everything is pretty by-the-book (or so I hope). My only major question is if I'm wiring up the crystal chamber LEDs correctly. I'm using three separate LEDs instead of a common cathode, but I'm wiring them with a common ground to the accent LED ground pad, basically making a DIY common cathode RGB LED (kinda-sorta). Is this okay, electronically speaking? And don't worry, I have plans for making the RGB LEDs diffuse and blend together to evenly illuminate the crystal.
Also, I'm assuming that all the PWM control signals for color channels 1, 2, and 3 are all 3.3V, and at a max current of 18mA. Correct?
The LEDs for the crystal chamber that I'm using are all rated for 20mA max, but I'm choosing to run them all at 15 mA (or 0.015 amps) just to be safe.
Red forward voltage (Vf) = 2.0
Blue Vf =3.0
Green Vf =3.0
My resistor calculations for the crystal chamber LEDs using Ohm's Law are as follows:
Red: 100 Ohm, 1/8 watt resistor
R = (3.3-2.0)/0.015 = 86.66 Ohms, so round up to 100 Ohms?
P = 86.66 x (0.015)2 = 0.01949 watts, so round up to 0.125 or 1/8 watt?
Blue: 20 Ohm, 1/8 watt resistor
R = (3.3-3.0)/0.015 = 20 Ohms, no rounding?
P = 20 x (0.015)2 = 0.0045 watts, so round up to 0.125 or 1/8 watt?
Green: 20 Ohm, 1/8 watt resistor (same Vf and current as the blue die)
R = (3.3-3.0)/0.015 = 20 Ohms, no rounding?
P = 20 x (0.015)2 = 0.0045 watts, so round up to 0.125 or 1/8 watt?
I've been wondering where the best electronic supply place is to find these small wattage resistors, as they aren't carried here at TCSS.... perhaps Mouser?
Thanks in advance for your comments and suggestions! :D