![]() Or to avoid that problem, you could use the opposite type of transistor to control each LED, but I've never needed to. Just make sure that your LED's can withstand the full supply worth of reverse voltage because they'll get that when the PWM is off and you're driving some LED's on and others off. Thus, OFF is still off, and ON is whatever brightness you set with the PWM generator. The PWM output then feeds one of these, depending on which is easier for you:Īs you can see, each LED is individually controlled from a digital output, and the common rail is controlled by the PWM'ed transistor. A 555 calculator may be useful because the voltage range is similar. ![]() Choose the capacitor for a low-ish frequency that is still higher than you can see, like maybe 30Hz or above. I would recommend 10k resistors all around because they're easy to get, as well as the pot. The reference is a front-panel potentiometer that is padded with fixed resistors to match the voltage range of the oscillator. This is a relaxation oscillator (the bottom part) compared to an adjustable reference (the top part). Simulate this circuit – Schematic created using CircuitLab ![]() I've done this as an overall dimmer for panel lights:
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |