Nokia Mobile Phones Limited

Jens Hedrich

Konrad Brisse

The invention relates to a voltage supply apparatus, in particular for a radio telephone, in a motor vehicle having a main voltage source (,) which is connected to one input (,) of a voltage matching circuit (,) which derives at least one supply voltage (U,, U,) for the radio telephone (,) from the voltage (U,, U,) present at its input, and an auxiliary voltage source (,) which can be connected via a controllable switch (,) to the input (,) of the voltage matching circuit (13). In order to ensure uninterrupted operation of the radio telephone (,) in the event of failure of the main voltage source (,), a voltage monitoring circuit (,) is provided, to which a voltage signal which corresponds to the voltage (U,) of the main voltage source is supplied and which supplies a switch control signal in order to connect the auxiliary voltage source (,) to the input of the voltage matching circuit (,) in an emergency in the event of failure of the main voltage source (,).

Voltage supply apparatus, in particular for a radio telephone in a motor vehicle

An electronic communications device contains at least two modules (7, 8) which are connected to one another via an optical bus (4). In an energy-saving mode, each of the modules (7, 8) is switched to receive with a sampling period (P) which is the same for all modules (7, 8), and for a sampling time interval (T) which is short in comparison with the sampling period (P). One of these modules (7, 8) sends an interrupt signal (I) to the optical bus (4), whose duration is equal to or longer than the sampling period (P). At the latest on reception of the interrupt signal (I), the other module (7, 8) is switched to permanent receive in the next sampling time interval, so that data communication can then take place via the optical bus (4).

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Bochum, Germany

Jens Hedrich