AndyLanderdahl
- Sep 8, 2015
- 4
- Joined
- Sep 8, 2015
- Messages
- 4
So I'm making a lamp for a friend of mine for her dorm room. It's a log with some glowing mushrooms on it basically.
Now I have two problems, or maybe one, not sure. I need to find a way to power 20 LEDs (3V 20ma) off 120VAC. Now I do have a 12V power supply that I think should work, but that would mean putting them in some series. Which would conflict with the next problem. She'd like each of the individual lights to breath on its own, but all together would work too. Now my second power option was all 20 in series with a 3.3k ohm resistor (rated at 2W) which as far as I know should work ok to dim them all with a sufficiently rated circuit (the only simple one I found was based on a 555 chip to power 1 LED). The whole resistor is only dissipating ~1.3W so I think 2W should be ok? But that doesn't account for the individual breathing effect.
Basically the best solution I've come up with was to make a breathing circuit for each LED and power them all in parallel, but this would take up a lot of space. And space is definitely at a premium. I looked into using a microprocessor, but I really couldn't find anything, and I know very, very little about them.
SO in short, I guess what I'm trying to say is, can someone suggest a solution to power 20 LEDs (3V 20ma) off 120VAC so that they each breathe independently (timing and frequency)? I do have a 12VDC power supply that I think can handle 1A, so that should sufficiently power it, I think 12V is a lot more manageable for this project.
Sorry, this is my first post, and I have a weird amount of electronics knowledge (I inexplicably know things, as well as don't know things (mostly only with IC chips though).
Now I have two problems, or maybe one, not sure. I need to find a way to power 20 LEDs (3V 20ma) off 120VAC. Now I do have a 12V power supply that I think should work, but that would mean putting them in some series. Which would conflict with the next problem. She'd like each of the individual lights to breath on its own, but all together would work too. Now my second power option was all 20 in series with a 3.3k ohm resistor (rated at 2W) which as far as I know should work ok to dim them all with a sufficiently rated circuit (the only simple one I found was based on a 555 chip to power 1 LED). The whole resistor is only dissipating ~1.3W so I think 2W should be ok? But that doesn't account for the individual breathing effect.
Basically the best solution I've come up with was to make a breathing circuit for each LED and power them all in parallel, but this would take up a lot of space. And space is definitely at a premium. I looked into using a microprocessor, but I really couldn't find anything, and I know very, very little about them.
SO in short, I guess what I'm trying to say is, can someone suggest a solution to power 20 LEDs (3V 20ma) off 120VAC so that they each breathe independently (timing and frequency)? I do have a 12VDC power supply that I think can handle 1A, so that should sufficiently power it, I think 12V is a lot more manageable for this project.
Sorry, this is my first post, and I have a weird amount of electronics knowledge (I inexplicably know things, as well as don't know things (mostly only with IC chips though).