For the power supply fischertechnik uses 2.6mm plugs and sockets .
The operating voltage is 9 volts at fischertechnik .

In addition to power supplies fischertechnik also offers accumulators.

If you have these on hand , you can not use other suitable power supplies.

These power supplies should provide a stabilized DC voltage of 9 volts. These should be permanently short -circuit proof and have a thermal fuse .
Use these power supplies only under supervision and not as a toy.
Use best a green switching power supply . It is economical and is not as hot as older devices .

Even if fischertechnik is somewhat tolerant of polarity reversal , note the polarity of the connections .

Note the warranty and safety of fischertechnik .

Are you using the ROBO TX Controller or the Robointerface must the power supply can deliver 2 A current.
In individual motors or lamps less sufficient .

To fischertechnik to connect to an alternate power supply, we have to build an adapter.

Step 1: The Adapter

We need the following parts:

a flat stone 15, an alternative mounting plate
two 2.6 mm jacks Marklin
two matching ring lugs
a suitable hollow socket

Drilling, screws, solder, done.

With a larger construction panel could still be integrated with a fuse holder.
Regardless of the power supply must be short-circuit proof.

Step 2: A 4 Mm Laboratory Adapter

If you have a lab power supply can also use this.
Please also do not use as children's toys.

In this case, let us build ourselves an adapter from 4 mm to 2.6 mm jacks.

In this example I've provided two aluminum plates with 2.6 mm holes.