Edit: Thanks so much for the effort in explaining but I think I can understand better if explained in the following context:
Board: Arduino Nano Power Source: 12v Transistor: TIP120 LED: 4 strips of LEDs that consume 30mA each at 12v (3528 type LEDs)
Scenario: I want to switch these LEDs from fully off to fully on continuously (so like fading, except turning them on) then fade them off. This accounts for 1 cycle.
Question: How do I calculate the amount of power dissipated by the transistor. If I can't calculate the exact wattage, is there a way I can approximate the maximum?
Thanks so much!
I've got a project to build a rather small LED controller for pwm fading. First off, what transistor should I use (or maybe MOSFET?) to control less than 500 mA without a heatsink? Secondly, how does one calculate the heat dissipated by the transistor during the switching cycle?
Do you guys think using transistors is the best way to approach this? Or is there a way to somehow increase the capability of arduino's limit to switch higher than 5v and greater than 40ma?
Thanks for the guidance.