The HUB DC is used as a ballast for the operation of C|Logline LON, Modbus and BACnet I/O modules for the rectification and smoothing of 24 V AC (alternating voltage). It supplies a smoothed direct voltage of approx. 33 V DC at the output (with 24 V AC at the input). Switching the supply voltage for C|Logline LON, Modbus and BACnet I/O modules from 24 V AC to DC operation (24 to 36 V DC) reduces the thermal load in the I/O modules and extends the service life of the components contained therein. The device is intended as a half-wave rectifier with a common ground point (input A2 = output 0 V) for direct use in 24 V AC systems.