Inverter for the switched-mode power supply units 66360/66361 or 60041/60061 for converting direct voltage into alternating voltage or for connecting accessories suitable for direct current. The alternating voltage can be used for solenoid items that have to be switched with alternating current, for level crossings and for supplying control devices that only work with alternating voltage (such as 6021, 6015, 6017). The direct voltage can be used, for example, to supply the system lighting or for accessories or control devices that are suitable for direct current. There is a hollow socket (for 66360) and a 4-pin mini-DIN high-current plug (for 60041) on the front, and a DC and an AC socket on the rear.