A power distribution system and method can include a controller and a set of power-using devices. Each power-using device in the set can include a sensor configured to measure a parameter and transmit a sensor signal representing the parameter to the controller, and the controller can respond to the transmitted sensor signal.

A method and apparatus are for monitoring a secondary power device and for accurately checking a state of the secondary power device, and an electronic system includes the apparatus. The method of monitoring a secondary power device includes setting a first reference parameter by using a voltage of at least one capacitor of the secondary power device, setting a second reference parameter by using the voltage of the at least one capacitor and the first reference parameter, and setting a reference level for checking of the state of the secondary power device by using the second reference parameter, wherein the reference level is used in checking of the state of the secondary power device.

A wireless power receiver includes a rectifier configured to convert a radio frequency (RF) voltage signal generated based on an RF input to a direct current (DC) voltage, and a boost converter configured to generate a voltage for battery charging using the RF voltage signal as a switching signal.

A circuit for converting a first voltage to a second voltage in a communication system is disclosed. The circuit includes a pass transistor including a first terminal, a second terminal and a gate, wherein the first terminal is coupled with the first voltage. The circuit is also includes an error amplifier. The error amplifier includes a first input that is coupled with a constant reference voltage and a second input that is coupled with a first switch that is coupled with an output port. A second switch is included and is coupled between the first voltage and an output of the error amplifier. The output of the error amplifier is coupled with the gate of the pass transistor. A third switch is included and is coupled between ground and the output of the error amplifier. The second switch is configured to be driven by a first one shot pulse generated from an input signal of the communication system and the third switch is configured to be driven by a second one shot pulse generated from the input signal.

It is disclosed an amplifier for driving a capacitive load, comprising an input terminal adapted to receive an input voltage signal, an output terminal adapted to drive the capacitive load, a linear amplification stage, switching amplification stage, a capacitor, a first switch and a measurement and control circuit. The measurement and control circuit is configured to: measure the value of the current generated at the output from the linear amplification stage and generate a driving voltage signal of the switching amplification stage; generate the first switching signal to open the first switch and generate an enabling signal to enable the operation of at least part of the switching amplification stage; generate the first switching signal to close the first switch and generate the enabling signal to disable the operation of the switching amplification stage; generate the first switching signal to open the first switch.

A method for controlling a current associated with a power converter may comprise controlling the current based on at least a peak current threshold level for the current and a valley current threshold level for the current, and further controlling the current based on a duration of time that the power converter spends in a switching state of the power converter.

A transient current in a rectifier circuit is efficiently reduced. In a rectifier circuit, a first rectifier is provided between the first terminal and a second terminal. In the rectifier circuit, when a switch element is turned ON, a primary winding current flows from a power source to a primary winding in a transformer. When the switch element is turned OFF, a second rectifier current flows from a secondary winding in the transformer to a second rectifier. When the second rectifier current flows, a first reverse voltage is applied between the first terminal and the second terminal. The first reverse voltage is a reverse voltage applied instantaneously.

A wireless power receiver includes a rectifier with first and second inputs coupled to first and second terminals of a receiver coil, and having a first output coupled to ground and a second output at which a rectified voltage is produced. A first switch is coupled between the second input and ground, and is controlled by a first gate voltage generated at a first node. A second switch is coupled between the first node and ground, and is controlled by a second gate voltage. The first gate voltage closes the first switch to couple the second input to ground when the rectified voltage is less than a threshold voltage, boosting the rectified voltage. The second gate voltage closes the second switch to cause the second gate voltage to be pulled to ground when the rectified voltage is greater than the threshold voltage, limiting the boosting of the rectified voltage.

A method for controlling a stepper motor includes calculating a duty cycle of a current provided to the stepper motor and comparing a difference, between the calculated duty cycle and a base duty cycle of current provided to the stepper motor under a base load condition, to a reference duty cycle value. The method also includes adjusting a peak current level of the current provided to the stepper motor responsive to the comparison.

A wall-mountable load control device may include an illuminated rotary knob for providing a nightlight feature. The load control device may be configured to control an intensity of a lighting load. The load control device may include a yoke adapted to be mounted to an electrical wall box, an enclosure attached to the yoke, a faceplate attached to the yoke and having an opening, a mounting member attached to the yoke, and/or a potentiometer located within the enclosure and having a shaft extending through an opening in the yoke and the opening of the faceplate. The load control device may include a collar attached to the boss of the mounting member and surrounding the shaft of the potentiometer. The mounting member may be configured to conduct light from at least one light source housed within the enclosure to illuminate the faceplate.