LED Lighting

Kedgar · February 12, 2020, 9:24pm

Hi I am working on a project that requires 24 VDC LED lighting to fade in and out once turned on. Does anyone have a solution ?

Thanks

Gavitron · February 12, 2020, 10:09pm

sounds like you just need a 24v PWM controller? Amazon.ca

lukecyca · February 12, 2020, 10:16pm

@Hekseskudd and @Rob_MacKenzie have been working on something quite similar. Theirs is dimming RGB strips, so 3 dimmable channels, whereas you only need one.

Rob_MacKenzie · February 12, 2020, 11:12pm

How many LEDs?
It’s not too hard to do this, as stated.

What do you mean by fade in and out?

Kedgar · February 12, 2020, 11:25pm

Hi Rob, by fading in and out, I mean a breathing effect once turned on. I have about 3 meters of led’s at 15 watts per meter.

Thanks

Rob_MacKenzie · February 13, 2020, 12:10am

Ok, so to get the breathing effect, you’ll want to get REALLY creative with a 555, or just toss a micro controller at it. Micro controller is easier, since you can just make changes with code, but 555 is kinda cool.

There seems to be a good number of tutorials online related to this kinda effect.

Somebody here could throw one together for a couple cases of beer.

Rob_MacKenzie · February 13, 2020, 12:27am

In fact, I remember this paper from a few years ago that studied the breathing light on macbooks.

https://avital.ca/notes/a-closer-look-at-apples-breathing-light

It has a really good write up on light output, PWM, and even has example code.

Kedgar · February 13, 2020, 12:39am

Hi thanks. If I want to proceed should I come by to touch base. If so which night is best for you?

Thanks again for your help.

Rob_MacKenzie · February 13, 2020, 12:43am

Next Tuesday, I’m out of town right now until then.

Kedgar · February 13, 2020, 12:55am

Ok I will connect with you next week. Thanks

Majicj · February 13, 2020, 5:58am

Should be easy with a Nano and the FastLED library.

https://www.reddit.com/r/arduino/comments/3rsjjo/led_strip_breathing_arduino/

https://www.reddit.com/r/FastLED/comments/aqv0es/fastled_breath_effect/

@Johnny5 can give you and hand with this appoach.

Hekseskudd · February 13, 2020, 5:27pm

Yeah my design uses non addressable RGB LEDs and is completely controlled with ‘live’ microcontroller controlled MOSFETs. Using something like 5v addressable LEDs is going to be way easier with the neopixel libraries. In my case the data sheet on the MOSFETs listed a signal range that was actually about 2 volts higher in reality which caused the MOSFETs to get super hot. and that’s not gewd…thanks to @Rob_MacKenzie and his oscilliscope/ electrosleuthing skills we figured that out. (Also proper MOSFETs from
@packetbob).

Kedgar · February 13, 2020, 6:20pm

Hi Jon, are you able to build me the unit? Also can we meet up either tomorrow afternoon or next Tues.

Thanks

Hekseskudd · February 13, 2020, 6:43pm

I am soooo busy currently, I won’t be able to help you out I don’t think. I do have a working lamp with about 15 feet of 24v LEDs that could do exactly what you are after (and more!) with just a simple reflash of the code. I would need to add up the parts cost plus a little of my time to get a price for you. I have not built an enclosure for it yet, just the working guts.

Hekseskudd · February 13, 2020, 6:46pm

Hekseskudd · February 13, 2020, 6:49pm

That’s the enclosure for the first lamp I made. You wouldn’t need any potentiometers for your application, just a micro, buckverter, MOSFETs, switch, psu.

Kedgar · February 13, 2020, 6:56pm

Hi thanks, so I have about 90 watts at 24 Vdc. I only need to be able to control the breathing pulse and get it where the client is happy. If your unit will work, I would be interested to get it.

Kedgar · February 13, 2020, 11:35pm

Hi Jon, sorry to bother you again. Can you give me a quick call if possible?

604 -626 - 6921

Thanks

Thovthe · February 14, 2020, 1:56am

This is a public section, just in case you didn’t know.

Rob_MacKenzie · February 17, 2020, 3:39pm

I can build it next week when I’m back in town as stated previously.