A solid state light source driver circuit that operates in either a buck convertor or a boost convertor configuration is provided. The driver circuit includes a controller, a boost switch circuit and a buck switch circuit, each coupled to the controller, and a feedback circuit, coupled to the light source. The feedback circuit provides feedback to the controller, representing a DC output of the driver circuit. The controller controls the boost switch circuit and the buck switch circuit in response to the feedback signal, to regulate current to the light source. The controller places the driver circuit in its boost converter configuration when the DC output is less than a rectified AC voltage coupled to the driver circuit at an input node. The controller places the driver circuit in its buck converter configuration when the DC output is greater than the rectified AC voltage at the input node.

A solid state light source driver circuit that operates in either a buck convertor or a boost convertor configuration is provided. The driver circuit includes a controller, a boost switch circuit and a buck switch circuit, each coupled to the controller, and a feedback circuit, coupled to the light source. The feedback circuit provides feedback to the controller, representing a DC output of the driver circuit. The controller controls the boost switch circuit and the buck switch circuit in response to the feedback signal, to regulate current to the light source. The controller places the driver circuit in its boost converter configuration when the DC output is less than a rectified AC voltage coupled to the driver circuit at an input node. The controller places the driver circuit in its buck converter configuration when the DC output is greater than the rectified AC voltage at the input node.

A circuit configuration for high-voltage tests includes an AC voltage source and at least two circuit branches, each of which can be electrically connected to the AC voltage source. An electrical AC voltage can be applied to a test object by a first circuit branch, and an electrical DC voltage can be applied to the test object by a second circuit branch which rectifies an AC voltage.

A motor control system includes a DC-to-DC converter including a semiconductor switch and a reactor that cooperates with the switch to convert input-side DC bus voltage across first and second input-side DC buses into predetermined output-side DC bus voltage across first and second output-side DC buses and to output the output-side voltage, control circuitry that controls duty factor of the switch and determine, based on input-side detection value of the input-side voltage and output-side detection value of the output-side voltage, whether there is failure in the system when the factor is 100 percent and reactor-current detection value of reactor current through the reactor is approximately zero, a smoothing capacitor connected to the output-side buses and disposed between the output-side buses, and an inverter that is connected to the capacitor through the output-side buses, converts DC power from the output-side buses into AC power and supplies the power to a motor.

A motor control system includes a DC-to-DC converter including a semiconductor switch and a reactor that cooperates with the switch to convert input-side DC bus voltage across first and second input-side DC buses into predetermined output-side DC bus voltage across first and second output-side DC buses and to output the output-side voltage, control circuitry that controls duty factor of the switch and determine, based on input-side detection value of the input-side voltage and output-side detection value of the output-side voltage, whether there is failure in the system when the factor is 100 percent and reactor-current detection value of reactor current through the reactor is approximately zero, a smoothing capacitor connected to the output-side buses and disposed between the output-side buses, and an inverter that is connected to the capacitor through the output-side buses, converts DC power from the output-side buses into AC power and supplies the power to a motor.

In embodiments of the invention, the present invention is directed to a contact hearing system including: a transmit coil positioned in an ear tip wherein the transmit coil includes an electrical coil wound on a ferrite core; a receive coil positioned on a contact hearing device wherein the receive coil includes an electrical coil without a core; a load connected to the receive coil; and a demodulation circuit connected to the receive coil and the load wherein the demodulation circuit includes a voltage doubler and a peak detector.

Various embodiments are directed to a switch circuit comprising: two terminal nodes, comprising an upper node and a lower node; a plurality of switch modules, connected in series between the upper node and the lower node, wherein each of the switch modules comprises a switch, a rectifier, and a capacitor; a connecting circuit, coupled to the switch modules; and a power converter, coupled to the connecting circuit and to a power sink. The switch circuit is configured to limit a voltage or a component of a voltage in the switch circuit, and to recover power from the limiting of the voltage, wherein recovering the power comprises diverting power from the switch modules via the connecting circuit to the power converter, and the power converter outputting the power to the power sink.

A circuit for controlling an electromechanical holding brake, includes: at least one halfwave rectifier, which generates a pulsed DC voltage from a mains AC voltage, and a phase gating circuit which is designed to generate a control signal for the electromechanical holding brake from the pulsed DC voltage by means of the phase gating.

A circuit for controlling an electromechanical holding brake, includes: at least one halfwave rectifier, which generates a pulsed DC voltage from a mains AC voltage, and a phase gating circuit which is designed to generate a control signal for the electromechanical holding brake from the pulsed DC voltage by means of the phase gating.

An electrosurgical assembly that includes one or more electrodes, and one or more AC conductors electrically connecting the one or more electrodes to a power source that is configured to generate and output an AC power signal to the one or more electrodes via the one or more AC conductors. A rectifier is electrically connected to the one or more AC conductors, and configured to convert the AC power signal into a DC power signal. A light source is electrically powered by the DC power signal.