Abstract: The present invention relates to a switched-mode power supply that comprises a detection circuit for detecting a coupling of an electrical device to the switched-mode power supply and a decoupling of the electrical device from the switched-mode power supply, a switch for controlling the supply of electric power to the switched-mode power supply, a control circuit for controlling the switch, the control circuit being configured to turn on the switch when the coupling of the electrical device has been detected, and to turn off the switch when the decoupling of the electrical device has been detected, and a supply circuit for providing a supply voltage to the detection circuit and the control circuit.

Abstract: A switched-mode power supply is disclosed, which includes a transformer with a primary winding and a secondary winding. A switch is coupled in series with the primary winding and configured to repeatedly interrupt a current through the primary winding. An inductor is located differently with reference to magnetic fields that the primary and secondary windings are configured to induce. A connection exists between the inductor and a circuit that contains one of the primary and secondary windings. The connection is configured to connect from the inductor to the circuit a first voltage that has a waveform representative of and a polarity opposite to a second voltage induced in the switched-mode power supply by leakage flux of the transformer at a switching moment of the switch.

Abstract: The present invention relates to an electrical contact device which comprises an electrically conductive base part, and an electrically conductive protruding part protruding from the electrically conductive base part. The electrical contact device also comprises an electrically conductive coil spring having a diameter that increases from a first end to a second end of the electrically conductive coil spring. The electrically conductive coil spring is arranged around the electrically conductive protruding part in such a manner that the first end of the electrically conductive coil spring faces the electrically conductive base part, and the electrically conductive coil spring extends further from the electrically conductive base part than the electrically conductive protruding part does.

Abstract: A switched-mode power supply comprises a transformer with a primary winding and a secondary winding. A switch is coupled in series with the primary winding and configured to repeatedly interrupt a current through the primary winding. An inductor is located differently with reference to magnetic fields that the primary and secondary windings are configured to induce. A connection exists between the inductor and a circuit that contains one of the primary and secondary windings. The connection is configured to connect from the inductor to the circuit a first voltage that has a waveform representative of and a polarity opposite to a second voltage induced in the switched-mode power supply by leakage flux of the transformer at a switching moment of the switch.

Abstract: The invention relates to a method and arrangement for detecting a situation in which an electrical device is connected to another electrical device. The electrical device comprises a first, second, and third electrical contact terminal (101, 102, 103). Non-zero voltage is arranged between the second and third electrical contact terminal. The other electrical device comprises counterparts (104, 105, 106) for the first, second, and third electrical contact terminal. There is a galvanic coupling (107) between the counterparts for the first and second electrical contact terminal. The arrangement comprises a resistor (108) between the first and second electrical contact terminal and a detector (112) for detecting the situation in which the electrical device is connected to the other electrical device on the basis of a change of an electrical quantity associated with the resistor. The first electrical contact terminal can be e.g. a metal shield on a USB-connector.

Abstract: A switched-mode power supply (200, 300, 400) comprises a primary side, a secondary side and a transformer (103, 303, 403) therebetween. An output on the secondary side delivers an output voltage and an output current to a load. An output voltage control circuit (110, 113, 801) keeps the output voltage at a first level, corresponding to a first output current value. A circuit element (201, 301, 401) integrates over time a voltage obtained from the transformer (103, 303, 403) and produces a signal indicative of the integrated voltage, corresponding to a second output current value that is smaller than the first output current value. An output voltage modifier (113, 601, 801) responds to the signal by changing the output voltage from the first level to a second level.

Abstract: A switched-mode power supply (200, 300, 400) comprises a primary side, a secondary side and a transformer (103, 303, 403) therebetween. An output on the secondary side delivers an output voltage and an output current to a load. An output voltage control circuit (110, 113, 801) keeps the output voltage at a first level, corresponding to a first output current value. A circuit element (201, 301, 401) integrates over time a voltage obtained from the transformer (103, 303, 403) and produces a signal indicative of the integrated voltage, corresponding to a second output current value that is smaller than the first output current value. An output voltage modifier (113, 601, 801) responds to the signal by changing the output voltage from the first level to a second level.