Vacuum cleaner with exchangeable accessory devices, has digital signals superposed on analogue signals in control line

摘要

A vacuum cleaner (1) has an electric motor and an exchangeable accessory device, in which an interface (7) besides two power lines (N,L) carries a control line for transmission of analogue signals into the accessory device (3). Digital signals can be superposed on the analogue signals on the control lines (8).