Hi all! New to the board! First off, I'm pretty well a noob when it comes to electronics. 25 years ago I built some circuits from some Radio Shack manuals (those were the days ), but I never understood exactly how the components interracted. Effectively, I could read basic and simple schematics, and use a soldering iron.
Now, I'm kind of getting bitten by the desire to learn more. I have a very basic grasp of what a resistor, capacitor, diode, etc. do, but I now need to know more. My method of learning is hands-on. Books suck.
Anyway, I'm trying to build a simple LED circuit using a RGB LED and potentiometers to control the intensity/brightness of each color. The power supply is 5V, max 100mA to work with.
The LED I purchased is Radio Shack P#276-028, 5MM LED. Green and Blue use 30mA, Red uses 50mA. At maximum power that is 110mA, over what I want to use.
Based on my limited knowledge, I think I want to wire this as such:
+5v > 56ohm R > Pot (120ohm) > Green leg
+5v > 56ohm R > Pot (120ohm) > Blue leg
+5v > 33ohm R > Pot (68 ohm) > Red leg
* I've heard that you actually want to put the resistors between the LED legs and ground, but I'd appreciate verification on it. *
My logic:
- The LED is 3.4v max, so based on an online LED resistor calculator, the resistors are what's needed to bring from 5v to 3.4v.
- Green and Blue - on the LED calculator, a pot capable of dropping voltage to .1v (basically turning off that color LED) is 120ohm.
- Red - on the LED calculator, a pot capable of dropping voltage to .1v (basically turning off that color LED) is 68ohm.
Am I anywhere near close, or will my house be reduced to ash in the not too far future?
I currently have some 1K pots at my disposal. They are rated at 50vdc at .1 watts. If I'm only putting 3.4v through them, will there be any problem using them for this project?
Thanks.
Now, I'm kind of getting bitten by the desire to learn more. I have a very basic grasp of what a resistor, capacitor, diode, etc. do, but I now need to know more. My method of learning is hands-on. Books suck.
Anyway, I'm trying to build a simple LED circuit using a RGB LED and potentiometers to control the intensity/brightness of each color. The power supply is 5V, max 100mA to work with.
The LED I purchased is Radio Shack P#276-028, 5MM LED. Green and Blue use 30mA, Red uses 50mA. At maximum power that is 110mA, over what I want to use.
Based on my limited knowledge, I think I want to wire this as such:
+5v > 56ohm R > Pot (120ohm) > Green leg
+5v > 56ohm R > Pot (120ohm) > Blue leg
+5v > 33ohm R > Pot (68 ohm) > Red leg
* I've heard that you actually want to put the resistors between the LED legs and ground, but I'd appreciate verification on it. *
My logic:
- The LED is 3.4v max, so based on an online LED resistor calculator, the resistors are what's needed to bring from 5v to 3.4v.
- Green and Blue - on the LED calculator, a pot capable of dropping voltage to .1v (basically turning off that color LED) is 120ohm.
- Red - on the LED calculator, a pot capable of dropping voltage to .1v (basically turning off that color LED) is 68ohm.
Am I anywhere near close, or will my house be reduced to ash in the not too far future?
I currently have some 1K pots at my disposal. They are rated at 50vdc at .1 watts. If I'm only putting 3.4v through them, will there be any problem using them for this project?
Thanks.