Electrical device having a power supply unit, a transformer power supply unit and a control card for an electrical device

In an electrical device for controlling functional units and processing data, for connection to an external data network communicating data network control signals including a ringing signal having an electrical power, and for switching between a quiescent state and an active state, the improvement comprising:

• means for controlling at least one of the functional units, said control means having lines to be connected to the external data network for receiving the data network control signals, and said control means starting data transmission from or to the electrical device after receiving the data network control signals;
• means for supplying energy to at least one of the functional units, said energy supply means having a primary side to be connected to a voltage supply network, said energy supply means connected to said control unit;
• means for switching between an open position and a closed position, said switching means:
• connected to and switching said at least one power supply unit;
• entering into said open position and disconnecting said primary side of said at least one power supply unit from the voltage supply network in the quiescent state;
• and
• entering into said closed position dependent only upon the electrical power received directly from the ringing signal in the active state;
• and
• said switching means remaining in one said positions based upon the energy from said at least one power supply unit.

A transformer power supply unit, comprising:

• a primary side to be connected to a voltage supply network having a network voltage;
• an electrical switch for selectively switching the network voltage on and off;
• a data line to be connected to an external data network transmitting a ringing signal having electrical power;
• and
• said switch:
• connected to said primary side and to said data line;
• opening, in a quiescent state, to disconnect said primary side from the voltage supply network;
• and
• closing, in an active state, to connect said primary side to the voltage supply network based only upon the electrical power of the ringing signal.