Telefonaktiebolaget Lm Ericsson (publ)

Carl-Henrik Jorgen Malmgren

Henrik Helmer Hellberg

Anders Emericks

Hans Oskar Eriksson

Mattias Israelsson

Elisabeth Maria Larsson

Henrik Sandstrom

Line circuits can be supplied with a first voltage or a second voltage of a lower absolute value. At least the second voltage is variable. The line voltages of at least active line circuits are measured, and possible values for the second voltage are prognosticated. It is determined which line circuits can be supplied with the respective possible value, and the power consumption of those line circuits is calculated using each possible value. For the line circuits which cannot be so supplied, the power consumption is calculated using the first voltage. For each possible value prognosticated for the second voltage, the total power consumptions are summed, and the value that gives the lowest total power consumption is selected as the second voltage. The line circuits are then supplied with the first voltage or the selected second voltage.

Method and arrangement for choosing supply voltage

The present invention relates to a method and a device for diversion of power in an electric circuit (,), e.g. a subscriber circuit with a balanced two-wire transmission, comprising a user (,) with a variable voltage requirement, which is controlled by the supply characteristic of the device and the resistance in the two-wire transmission (A,B,L). The voltage requirement of the user is fed back via a reference signal (U,) to an input of a voltage-regulating circuit (,), which supplies the user with a drive voltage (V,) adapted to the value of the reference signal. The voltage-regulating circuit (,) is fed with a supply voltage (V,) and a regulator voltage (V,) is defined as the difference between the drive voltage (V,) and the supply voltage (V,). Parallel with the voltage-regulating circuit, an external device (,), e.g. a resistance, is connected in order to divert an undesired power generation in the voltage-regulating circuit through the whole or part of the supply current of the user being led to the external resistance and there the whole or part of the power generation is emitted.

System and method for dissipating heat in an electric device

In a subscriber line interface circuit connected to a telephone line having a high potential wire and a low potential wire, an arrangement for generating a signal for determining the line voltage comprises means (,) for alternately charging a capacitor (,), by means of a first DC current, to a first voltage, and discharging the capacitor (,), by means of a second DC current, to a second voltage. Hereby, a sawtooth wave having an amplitude corresponding to the difference between the first and second voltages is produced. This sawtooth wave is converted to a pulse train related to the line voltage, from which the line voltage can be determined.

Arrangement in a subscriber line interface circuit

In a method and an arrangement for controlling the operating mode of a subscriber line interface circuit by mode control signals from a control circuit which is connected to the subscriber line interface circuit, the subscriber line interface circuit includes at least one latch which is interconnected between the control circuit and the subscriber line interface circuit. The latch is adapted to latch the mode control signals received from the control circuit in response to latch enable signals received from the control circuit, and to apply those latched mode control signals to the subscriber line interface circuit to control its operating mode.

Method and an arrangement for controlling the operating mode of a

In a subscriber line interface circuit connected to a two-wire telephone line (A and B lines) for transmitting AC signals, one of the wires (e.g., the A line) is set to a DC voltage lower (i.e., more negative) than a first DC voltage (GND), while the second wire (e.g., the B wire) is set to a DC voltage lower than the DC voltage of the first wire, but higher than a second DC voltage (VREG). A first voltage generator is provided for setting a first threshold voltage (VTHA) between the first DC voltage (GND) and the DC voltage of the first wire. A second voltage generator is provided for setting a second threshold voltage (VTHB) between the second DC voltage (VREG) and the D voltage for the second wire. The first and second threshold voltages are utilized for transmission and reception of AC signals on the respective A and B wires. As long as the instantaneous value (VA) of the signal on the first wire (A) equals the first threshold voltage (VTHA) and/or the instantaneous value (VB) of the signal on the second wire (B) equals the second threshold voltage (VTHB), the subscriber line interface circuit automatically adjusts the signal headroom to the actual amplitude of the AC signals by controlling the voltage difference (VA) between the first DC voltage (GND) and the DC voltage of the first wire (A) and/or the voltage difference (VB) between the DC voltage of the second wire (B) and the second DC voltage (VREG).

Growing community of inventors

Stockholm, Sweden

Carl-Henrik Jorgen Malmgren