I have a large layout that I want to do some lighting effects, one is to go form daylight to dusk ( sun set) to ,
involving a sunset to moonlight all of this is on 120v system I want a smooth transition to the scenes
In my buildings and street lights are all 12 v system for LED's , I want them to come on a different times, staged. So what and how do I do this.
Thanks Mark Gardner
Some mains dimmers, some transistors and some software.
Have a look at blink without delay for some more clues.
Hi,
120V stuff needs AC power control like THIS for On-Off. Dimming 120VAC from arduinois a little more complex.
The 12V (DC, right?) can be dimmed with power FET switches like THESE (or build your own)..
Plain on-off can use relays for any power.
See THIS for overall info on controlling power with Arduino.
DISCLAIMER: Mentioned stuff from my own shop...
Have a look for remote controlled dimmers.
IR would probably be the easiest.
That way you only have to worry about the control side and have no problems with the mains side (they already have the required approvals for connection to utility mains).
Of course it's a large layout, ...it's O-gauge!! (Do HO myself).
You say you are running 12vdc for lighting. Is this off the throttle transformer? Do you know what current it can do? How many leds are you talking, and how many watts?
Since you are presumably working in O-scale, you can do some cool stuff with small smd leds, like make table lamps work and not look out of proportion.
If you are looking at doing dozens of leds, ranging from smd to power leds (work lights, etc) you might want to consider making the lighting a standalone system to not overtax the system. I guess the big question is how much are you willing to spend to do this (not so much upfront, but in the end)
Photo resistors and BJT's are fairly cheap and could be used independently of other scenes for typical 20mA leds, and in O-scale , might be similar to a 150W incandescent bulb (real world)
Guess I'm starting to drift off into my own layout that I've been neglecting to work on......
One question you need to address is color temperature - if you are using LEDs for example - do you just want the light intensity to change for the transition or do you expect to go from white to the yellow/orange glow of sunset etc. ? That would make it more complex, but be more realistic. Tungsten type lights on a dimmer would give a color shift, but LED's don't shift very well so if that is important to you ...
Ok most likely will do a Lutron system for the 120v system, this looks the simplest. for the DC system 12v and 3v leds I will want a system I can program. If I can program it LOL. So basically it is lighting up street lights, buildings, some scenes in building such as welders, Hobo camp fires, Head lights on trucks. I love the little LED's
so direct me in the right direction .
Thanks Mark
scooterpd:
So basically it is lighting up street lights, buildings, some scenes in building such as welders, Hobo camp fires, Head lights on trucks. I love the little LED's
There's "little leds" and then there's REALLY "little leds". The smallest are 0402. That's .04" x .02". Probably not very useful for streetlights, but would work great for any light source that's approx a scale 3in or where hidden lighting is needed.
There are several sizes and power levels for the surface mount leds, which may prove to be the most useful for lighting you can see. Current requirements must be accounted for in planning this, with the small indicator leds typically drawing 20mA to lighting leds pulling up to 1A.
You would really need to figure up exactly how many leds you want to use, and of what type. Some creative circuitry can turn groups on together, and would be simplified if all in the group needed similar power (current).
If you are talking hundreds of leds, then it may take time and effort to get them in place and wired. It might be good to break it down into scenes and go modular.
I don't think the programming would be hard (I'm by no means an expert--I'm new as well but grasp the concepts), having traffic signals and random lights being the biggest part of it.
I guess the big question is,
-how many leds?
-current rating for them
-what will your 12v supply handle (current rating) (Is is the supply on the transformer?)
I'm not sure about bang for the buck but have you looked into fiber optics?
Might be more tangle trouble than it's worth.