Lighting for model Railway

[jameske]

I am wanting to make a lighting setup for my brothers model railway.
The idea was to have a seperate box where the lights are to be plugged in. This box needs to have at least 20 channels for the lights to plug into.
The box will run at 12V DC maximum.

On the other end will be the control unit that allows the user to take control of the lights (either dimmed to a certain brightness or turnned off or on fully).

The two ends of the project will be wired together.

Has anyone got any ideas of how I could do this project with the two boxes wired up without 20 figure 8 cables?

 

[mike_k]

have a look at About MERG

 

[Hero999]

You haven't given enough information.

Does every light need to be controlled individually or is it all right to have them all at the same brightness?

For 12V I'd recommend a wall plug.

I'd recommend using LEDs rather than incandescents.

 

[jameske]

Sorry, all the 20 channels will need to be controlled individually (multiple lights will be on each channel and won't need individual controls).
Both incandescents and LEDs will be used (More LEDs though).

please say if this doesn't make sense.

 

[kpatz]

How far apart will the two boxes (control box and light power box) be?

You could put a microcontroller with sufficient I/O pins (20 plus whatever you need for control input) in the light power box. The MCU would control the lights via the I/O pins, either on, off, or dimmed via PWM. Each pin would need a transistor driver capable of delivering the proper voltage/current to the LEDs or bulbs (what voltage bulbs are you using)?

The control box would contain another microcontroller that reads the controls (buttons/switches/etc.) and sends data to the power box over a cable using a serial protocol like I2C or RS232/485 or whatever.

Not exactly a beginner project.

 

[jameske]

The two boxes will be 5m apart maximum.
I have been thinking about using DMX.
My question now is how!!

 

[Hero999]

It still depends on exactly how you want to control the lights.

If they're 20 low current lights you could simply use a piece of ribbon cable with 21 conductors, one for return and the others for each light and have an array of 20 small switches. The return conductor might need to be a heavier gauge capable of carrying the current for all the lamps.

If the lamps are high current you could run two power lines and just use 20 core ribbon cable for a control signal to an array of 20 transistors .

If you want to make it more complicated use a micro controller at each end and you'll only need three wires, two for the power supply and one for the signal. You could also program it to flash the lights in a fancy pattern.