Hi tthere. I'm still pretty new to electronics, starting out by learning some simple computer mods. I've been building a computer from sheet aluminum, based on a sweet looking pyramid-shaped CD Player I saw at Radioshack.
Older 3d Model: **broken link removed**
Actual thing (so far): **broken link removed**
Anyway, I'm wiring up some 3mm 3v LEDs, and I'm trying to figure out the resistance needed. I keep coming accross the formula R = (5 - V) / I, where V is the voltage that I want the LEDs to have, 5 is the amount I'm feeding it (from my computer's power supply), and I would be the LED's mA (.02A per LED).
The problem I'm having is that I think I'm doing something wrong with calculating the total amount of resistance I'll need. For an example, I'm going to have 4 LEDs hooked up in parallel, and I want them to have 1v each. I tried multiplying the amperage by 4 (.08 instead of .02), giving me the formula;
R = (5v - 1v) / .08
...but the LEDs appear to be at full brightness. (In case I'm just picking the wrong resistor, I'm using a 47 ohm, yellow-purple-brown-gold resistor, the closest to 50 ohms that I have).
Please give me any insight you have as to what I'm doing wrong, whether it's in calculating the resistance or just using the wrong components. Thanks in advance.![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Older 3d Model: **broken link removed**
Actual thing (so far): **broken link removed**
Anyway, I'm wiring up some 3mm 3v LEDs, and I'm trying to figure out the resistance needed. I keep coming accross the formula R = (5 - V) / I, where V is the voltage that I want the LEDs to have, 5 is the amount I'm feeding it (from my computer's power supply), and I would be the LED's mA (.02A per LED).
The problem I'm having is that I think I'm doing something wrong with calculating the total amount of resistance I'll need. For an example, I'm going to have 4 LEDs hooked up in parallel, and I want them to have 1v each. I tried multiplying the amperage by 4 (.08 instead of .02), giving me the formula;
R = (5v - 1v) / .08
...but the LEDs appear to be at full brightness. (In case I'm just picking the wrong resistor, I'm using a 47 ohm, yellow-purple-brown-gold resistor, the closest to 50 ohms that I have).
Please give me any insight you have as to what I'm doing wrong, whether it's in calculating the resistance or just using the wrong components. Thanks in advance.