Abstract: A self-regulating power supply (601, 901) for a led light source comprises a drive power input (602, 603) and a lighting output (604, 605, 904, 905), and therebetween a converter (606, 906) for generating a supply voltage and a supply current from drive power. In addition, it comprises voltage regulating means (607, 907), current regulating means (608, 908), and a control unit (609, 909) which controls said voltage and current regulating means (607, 608, 907, 908). The control unit (609, 909) is arranged to change (701, 802) the supply voltage in a controlled manner to detect where an operating voltage range of the led light source lies, and to measure (703, 803, 806) a value of the supply current in the operating voltage range. It deduces (702, 704) a nominal maximum value of the supply current at least partly on the basis of the measurement of the value of the supply current, and sets (705) the deduced nominal maximum value of the supply current as a target value of the supply current.

Abstract: A self-regulating power supply (601, 901) for a led light source comprises a drive power input (602, 603) and a lighting output (604, 605, 904, 905), and therebetween a converter (606, 906) for generating a supply voltage and a supply current from drive power. In addition, it comprises voltage regulating means (607, 907), current regulating means (608, 908), and a control unit (609, 909) which controls said voltage and current regulating means (607, 608, 907, 908). The control unit (609, 909) is arranged to change (701, 802) the supply voltage in a controlled manner to detect where an operating voltage range of the led light source lies, and to measure (703, 803, 806) a value of the supply current in the operating voltage range. It deduces (702, 704) a nominal maximum value of the supply current at least partly on the basis of the measurement of the value of the supply current, and sets (705) the deduced nominal maximum value of the supply current as a target value of the supply current.

Abstract: An electronic device (201) of a transportation means comprises a power bus input interface (202), a power bus output interface (203), and a data bus interface (204). The device comprises voltage reducing means (205) for selectively performing a controlled voltage reduction between the power bus input interface (202) and the power bus output interface (203). The reduced operating voltage is lower than the operating voltage received via the power bus input interface (202) but higher than zero. The device is arranged to use (1201, 1202) said voltage reducing means depending in a predetermined manner on whether or not the device has performed addressing operations to carry out addressed data communication by means of said data bus.

Abstract: An electronic device (201) of a transportation means comprises a power bus input interface (202), a power bus output interface (203), and a data bus interface (204). The device comprises voltage reducing means (205) for selectively performing a controlled voltage reduction between the power bus input interface (202) and the power bus output interface (203). The reduced operating voltage is lower than the operating voltage received via the power bus input interface (202) but higher than zero. The device is arranged to use (1201, 1202) said voltage reducing means depending in a predetermined manner on whether or not the device has performed addressing operations to carry out addressed data communication by means of said data bus.

Abstract: The control device for the luminaire of a vehicle has an operating power input (401) for receiving operating power, an illumination output (402) for supplying illumination power to one or more light sources (403), and a power converter (404) coupled between said operating power input (401) and said illumination output (402) for converting received operating power into illumination power, which is directed outside. The power converter (404) has a control connection (405). The control device has a control data connection (406) for transmitting control data, and a controller circuit (407) coupled between said control data connection (406) and said control connection (405). The control device has a control power input (408) separate from said operating power input (401) for receiving control power to said controller circuit (407) independently of said operating power, as well as a galvanic isolation (409) between said control circuit (407) and said power converter (407).

Abstract: The control device for the luminaire of a vehicle has an operating power input (401) for receiving operating power, an illumination output (402) for supplying illumination power to one or more light sources (403), and a power converter (404) coupled between said operating power input (401) and said illumination output (402) for converting received operating power into illumination power, which is directed outside. The power converter (404) has a control connection (405). The control device has a control data connection (406) for transmitting control data, and a controller circuit (407) coupled between said control data connection (406) and said control connection (405). The control device has a control power input (408) separate from said operating power input (401) for receiving control power to said controller circuit (407) independently of said operating power, as well as a galvanic isolation (409) between said control circuit (407) and said power converter (407).

Abstract: The aim of this invention is an arrangement for displaying and updating information with the use of controllable display units, which display units contain at least one display laminate equipped with an essentially thin display which can be updated. The display laminate is arranged for positioning in an essentially transparent pocket-like space, which space also has the ability to contain, in addition to the display laminate, a sheet of paper or a similar sheet or label containing additional information in text or image form.