An electronic device may include a main circuit including multiple sub-circuits powered by a direct-current (DC) power supply circuit. The main circuit has a main circuit current demand being a time-varying demand for a DC voltage-regulated supply current being a function of a number of the sub-circuits being active. The DC power supply circuit may include multiple DC voltage regulators to provide the main circuit with the supply current and a command decoding and power management circuit to control enablement of the voltage regulators. The command decoding and power management circuit may be configured to detect an instant value of the main circuit current demand and to selectively enable one or more of the voltage regulators based on the detected instant value.

The present invention provides for a high voltage direct current power supply including a primary high voltage direct current supply offering a primary output; a floating secondary output floating with respect to the primary output and fed by the primary output: an output terminal at the floating secondary output for providing an output voltage; a controller operative to detect a change in the output voltage at the output terminal and to generate a control signal responsive to the change in output voltage; and a controllable current source, which can comprise a programmable current source, arranged to provide current at the floating secondary output responsive to the said control signal and whereby the said current is provided to reduce charging of a secondary output capacitance as the output voltage changes.

An electronic device may include a main circuit including multiple sub-circuits powered by a direct-current (DC) power supply circuit. The main circuit has a main circuit current demand being a time-varying demand for a DC voltage-regulated supply current being a function of a number of the sub-circuits being active. The DC power supply circuit may include multiple DC voltage regulators to provide the main circuit with the supply current and a command decoding and power management circuit to control enablement of the voltage regulators. The command decoding and power management circuit may be configured to detect an instant value of the main circuit current demand and to selectively enable one or more of the voltage regulators based on the detected instant value.

An electronic device may include a main circuit including multiple sub-circuits powered by a direct-current (DC) power supply circuit. The main circuit has a main circuit current demand being a time-varying demand for a DC voltage-regulated supply current being a function of a number of the sub-circuits being active. The DC power supply circuit may include multiple DC voltage regulators to provide the main circuit with the supply current and a command decoding and power management circuit to control enablement of the voltage regulators. The command decoding and power management circuit may be configured to detect an instant value of the main circuit current demand and to selectively enable one or more of the voltage regulators based on the detected instant value.

A power supply circuit for providing a positive, intermediate, and negative voltage supply includes positive and negative DC voltage buses that connect to a power source; a first voltage divider that is connected between the positive and the negative DC voltage buses, that includes a first transistor connected to the negative DC voltage bus, and that provides the intermediate voltage supply; a second voltage divider that is connected between the positive and the negative DC voltage buses and that is connected to the first transistor; and a short circuit protection module that includes a second transistor connected between outputs of the first and second voltage dividers and connected to the first transistor and that includes a current limiting element connected to the first transistor and configured to limit power dissipated by the first transistor in the case of a short circuit to the intermediate voltage supply.

A power managing system and method are provided. When an under voltage lockout circuit determines that a common voltage of the power managing system is lower than a first lockout voltage, the under voltage lockout circuit outputs a first under voltage lockout signal for controlling one of a plurality of power converters that supplies a highest output voltage to rapidly reduce its output voltage to a zero value. Then, the under voltage lockout circuit outputs a second under voltage lockout signal for controlling another one of the power converters that supplies a lowest output voltage to gradually reduce its output voltage to the zero value.

A power managing system and method are provided. When an under voltage lockout circuit determines that a common voltage of the power managing system is lower than a first lockout voltage, the under voltage lockout circuit outputs a first under voltage lockout signal for controlling one of a plurality of power converters that supplies a highest output voltage to rapidly reduce its output voltage to a zero value. Then, the under voltage lockout circuit outputs a second under voltage lockout signal for controlling another one of the power converters that supplies a lowest output voltage to gradually reduce its output voltage to the zero value.

An impedance measurement circuit includes a signal injector having a voltage input and a voltage output, a controllable switch, and a voltage drop device connected in parallel with the controllable switch between the voltage input and the voltage output. The voltage output is connected to a load. A voltage sensor is configured to measure a voltage across the load. A current sensor is configured to measure a current draw of the load. A computing device is configured to determine an impedance of the load at a frequency based on the measured voltage and the measured current. The computing device controls the switch based on the frequency.

An impedance measurement circuit includes a signal injector having a voltage input and a voltage output, a controllable switch, and a voltage drop device connected in parallel with the controllable switch between the voltage input and the voltage output. The voltage output is connected to a load. A voltage sensor is configured to measure a voltage across the load. A current sensor is configured to measure a current draw of the load. A computing device is configured to determine an impedance of the load at a frequency based on the measured voltage and the measured current. The computing device controls the switch based on the frequency.

In an embodiment an electronic load for installation in a power supply of a vehicle lamp includes a first connection node connected to two first connection sections adapted to be connected between respective corresponding connection sections of a first line carrying a voltage potential, a second connection node connected to two second connection sections adapted to be connected between respective corresponding connection sections of a second line carrying a reference potential, wherein a difference between the voltage potential and the reference potential comprises a supply voltage configured to be supplied to the vehicle lamp and a current sink circuit coupled between the first and second connection nodes, the current sink circuit configured to cause a substantially constant current flow independently of a time-varying supply voltage from at least one of the first connection sections to at least one of the second connection sections.