Søren's Model Railway Pages

About model railways in H0


Using The Märklin m83 For Lighting

The Märklin m83 decoder is first and foremost a solenoid accessory decoder. A solenoid accessory can be a turnout motor or an uncouple track. The m83 can also control lighting on your layout.

It could control:

  • A grade crossing light
  • Street lighting
  • House lighting

Basically any light you can think of. The m83 also has several light effects that you can use.

The set up is simple and you only need a 1k Ohm resistor for the job. I find it useful to have an assortment of resistors lying around. I used a 1.5k Ohm resistor for this example, but a 1k Ohm will be sufficient. Unfortunately the manual does not speak of this and I have had a few questions regarding the subject of the m83 controlling lighting where people cannot get it to work.

The reason is that the m83 has a small amount of current running through the active port at all time. When the port is inactive, it still has a small amount of current running through it. This current is enough to power the LEDs in a lamp post or a house. The user will experience this as being unable to turn off the light completely.

The solution is simple though: You take your resistor and bridge the output of the m83. That way the resistor will eat the remaining current when the power is supposed to be off and the LED will turn off.

A model train
Use a 1k Ohm resistor to bridge the output ports and eat the power when the port is inactive.

Why does the port still has current when it is supposed to be off? Well, one can only guess, but my guess is that Märklin prepared the m83 to feedback the position of turnouts. This could explain this type of behaviour. Doing so is useful in situations with turnouts, but I expected the port to turn off completely when I configured the port's behaviour from solenoid control to light control. Unfortunately, this does not happen. That is why we need the resistor, it will eat the remaining current and the LED will turn off.

Here are some pictures of the m83 operating my new yard light.

A model trainOn!

A model trainOff!

Here is a video of the m83 operating my yard light.

Notice that the light turns on simulating fluorescent light. This is a feature of the m83, you can change the on/off behaviour of light to perform all sorts of effects. Check out my article on the subject

Happy modelling!