A radio frequency (“RF”) power device includes a RF power transistor, and a bias circuit coupled between a reference voltage input and an input terminal of the RF power transistor. The bias circuit includes an impedance control circuit that is configured to vary an impedance of the bias circuit at the input terminal of the RF power transistor responsive to a RF input signal provided to the input terminal, and/or a current control circuit that is configured to control a bias current provided to the input terminal of the RF power transistor responsive to variations in operating characteristics of the RF power transistor. Related RF power amplifiers and device packages are also discussed.

A constant voltage circuit amplifies an error between a reference voltage and an output voltage by an operational amplifier, and controls a load current based on the amplified voltage so that the output voltage becomes a constant voltage. The constant voltage circuit includes voltage detector means that detects only AC components of the output voltage limited to a predetermined band and outputs a detected voltage; voltage amplifier means that amplifies AC components of the detected voltage and outputs an amplified voltage; judgment means that outputs a judgment signal indicating whether or not the amplified voltage equal to or larger than a predetermined threshold; and controller means configured to increase a current value of the constant current source included in the operational amplifier, based on the judgment signal, thereby temporarily increasing a current consumption of the operational amplifier.

A constant voltage circuit amplifies an error between a reference voltage and an output voltage by an operational amplifier, and controls a load current based on the amplified voltage so that the output voltage becomes a constant voltage. The constant voltage circuit includes voltage detector means that detects only AC components of the output voltage limited to a predetermined band and outputs a detected voltage; voltage amplifier means that amplifies AC components of the detected voltage and outputs an amplified voltage; judgment means that outputs a judgment signal indicating whether or not the amplified voltage equal to or larger than a predetermined threshold; and controller means configured to increase a current value of the constant current source included in the operational amplifier, based on the judgment signal, thereby temporarily increasing a current consumption of the operational amplifier.

A cascading tap changing regulator has a set of input taps to power multiple stages of the cascade. Each tap in the set of taps is selectively engagable in respective on-off modes to effect a number of regulation steps, and a ratio of the number of steps to the number of taps in the set is greater than 1:1.

A cascading tap changing regulator has a set of input taps to power multiple stages of the cascade. Each tap in the set of taps is selectively engagable in respective on-off modes to effect a number of regulation steps, and a ratio of the number of steps to the number of taps in the set is greater than 1:1.

According to various embodiments, an intelligent electronic device IED, such as a protective relay, includes a universal binary input circuit for receiving an AC or DC binary input with a voltage magnitude between approximately 0 Volts and 300 Volts. The universal binary input provides reinforced isolation via an input protection subcircuit and an optocoupler for communicating an optical signal with an electrically isolated controller based on the received binary input signal. In one embodiment, a duty cycle modulation subcircuit generates a pulse width modulated drive signal to drive the optocoupler based on the voltage magnitude of the received binary input. The duty cycle of the pulse width modulated drive signal is (linearly or nonlinearly) inversely proportional to the voltage magnitude of the received binary input.

An intelligent current control apparatus provides a current control for a power supply branch and a load. The intelligent current control apparatus includes at least one power conversion unit and a control unit. The control unit controls a total phase current, which is composed of a single-phase current and a household phase current in the same phase, to be less than or equal to a rated phase current of the power supply branch.

An intelligent current control apparatus provides a current control for a power supply branch and a load. The intelligent current control apparatus includes at least one power conversion unit and a control unit. The control unit controls a total phase current, which is composed of a single-phase current and a household phase current in the same phase, to be less than or equal to a rated phase current of the power supply branch.

The present invention is directed to an electrical wiring device that includes a housing assembly having a plurality of terminals at least partially disposed therein, the plurality of terminals being configured to be coupled to an AC power source and at least one electrical load, the plurality of terminals being configured to provide the electrical wiring device with regulated AC power in a device energized state. At least one variable control mechanism is coupled to the housing assembly, the at least one variable control mechanism being configured to regulate power to the at least one electrical load by way of a control knob being user settable between a first adjustment stop and a second adjustment stop. A user accessible calibration button is included. At least one series pass element coupled to the at least one variable control mechanism, the at least one series pass element being configured to provide load power to the at least one electrical load in accordance with a user setting of the control knob. A regulation circuit is coupled to the user accessible calibration button and the at least one series pass element, the regulation circuit being configured to enter a calibration mode when the control knob is at or near the first adjustment stop or the second adjustment stop and the user manually actuates the calibration button, the regulation circuit establishing at least one pre-determined load power setting when the calibration button is actuated when the regulation circuit is in the calibration mode.

The present invention is directed to an electrical wiring device that includes a housing assembly having a plurality of terminals at least partially disposed therein, the plurality of terminals being configured to be coupled to an AC power source and at least one electrical load, the plurality of terminals being configured to provide the electrical wiring device with regulated AC power in a device energized state. At least one variable control mechanism is coupled to the housing assembly, the at least one variable control mechanism being configured to regulate power to the at least one electrical load by way of a control knob being user settable between a first adjustment stop and a second adjustment stop. A user accessible calibration button is included. At least one series pass element coupled to the at least one variable control mechanism, the at least one series pass element being configured to provide load power to the at least one electrical load in accordance with a user setting of the control knob. A regulation circuit is coupled to the user accessible calibration button and the at least one series pass element, the regulation circuit being configured to enter a calibration mode when the control knob is at or near the first adjustment stop or the second adjustment stop and the user manually actuates the calibration button, the regulation circuit establishing at least one pre-determined load power setting when the calibration button is actuated when the regulation circuit is in the calibration mode.