A load control device may control the amount of power provided to an electrical load utilizing a phase control signal that operates in a reverse phase control mode, a center phase control mode, and a forward phase control mode. A load control device may be configured to determine that the electrical load should be operated via a phase control signal operating in a forward phase-control mode. After determining to operate the electrical load via the phase control signal in the forward phase-control mode, the load control device may provide the phase control signal in a reverse phase-control mode for a predetermined period of time to the electrical load, for example, to charge a bus capacitor of the electrical load. Subsequently, the load control device may be configured to switch the phase control signal to the forward phase-control mode and provide the phase control signal in the forward phase-control mode to the electrical load.

A load control device may control the amount of power provided to an electrical load utilizing a phase control signal that operates in a reverse phase control mode, a center phase control mode, and a forward phase control mode. A load control device may be configured to determine that the electrical load should be operated via a phase control signal operating in a forward phase-control mode. After determining to operate the electrical load via the phase control signal in the forward phase-control mode, the load control device may provide the phase control signal in a reverse phase-control mode for a predetermined period of time to the electrical load, for example, to charge a bus capacitor of the electrical load. Subsequently, the load control device may be configured to switch the phase control signal to the forward phase-control mode and provide the phase control signal in the forward phase-control mode to the electrical load.

A method of commutation in a matrix rectifier from an active vector to a zero vector includes two steps. A method of commutation in a matrix rectifier from a zero vector to an active vector includes three steps.

A gyroscopic exercise apparatus, comprising: at least one control-moment gyroscope; at least one motion sensor for sensing movement of the apparatus; at least one spindle motor for providing rotation to a rotor of the gyroscope; and, at least one reversible motor for providing rotation to at least one gimbal of the gyroscope.

A gyroscopic exercise apparatus, comprising: at least one control-moment gyroscope; at least one motion sensor for sensing movement of the apparatus; at least one spindle motor for providing rotation to a rotor of the gyroscope; and, at least one reversible motor for providing rotation to at least one gimbal of the gyroscope.

A load control device may control the amount of power provided to an electrical load utilizing a phase control signal that operates in a reverse phase control mode, a center phase control mode, and a forward phase control mode. A load control device may be configured to determine that the electrical load should be operated via a phase control signal operating in a forward phase-control mode. After determining to operate the electrical load via the phase control signal in the forward phase-control mode, the load control device may provide the phase control signal in a reverse phase-control mode for a predetermined period of time to the electrical load, for example, to charge a bus capacitor of the electrical load. Subsequently, the load control device may be configured to switch the phase control signal to the forward phase-control mode and provide the phase control signal in the forward phase-control mode to the electrical load.

A load control device may control the amount of power provided to an electrical load utilizing a phase control signal that operates in a reverse phase control mode, a center phase control mode, and a forward phase control mode. A load control device may be configured to determine that the electrical load should be operated via a phase control signal operating in a forward phase-control mode. After determining to operate the electrical load via the phase control signal in the forward phase-control mode, the load control device may provide the phase control signal in a reverse phase-control mode for a predetermined period of time to the electrical load, for example, to charge a bus capacitor of the electrical load. Subsequently, the load control device may be configured to switch the phase control signal to the forward phase-control mode and provide the phase control signal in the forward phase-control mode to the electrical load.

Double sided versions of several power transistor types are devices that are already known in the literature. Devices built in this configuration are generally required to have a separate driver circuit to control the front and rear control electrodes and provide the gate or base voltage and/or currents for the power switch. This is because there may be of the order of 1000V potential-difference between the frontside and rearside potentials when the transistor is in the off conditionand a single integrated circuit cannot generally sustain this within a single package. The NPN configuration is preferred in this case to benefit from electron conduction for the main power path between the emitters. However, problems arising when using a P-type wafer. The present invention seeks to avoid the use of P-type wafers while still getting the higher conduction performance of NPN operation.

A power controller system comprises multiple power controllers that receive a periodic waveform input and that apply power to multiple loads. A switch-on time and a switch-off time is for each of the power controllers within a cycle of the periodic waveform input. The power controllers generate output waveforms to be applied to the loads that are partial segments of the cycle of the periodic waveform input. Each of the power controllers includes a switchable power component that can be switched on and switched off at any time and that can conduct current in both forward and reverse directions.

An apparatus for high-speed switching between a plurality of power sources includes a switch-mode isolation transformer. The switch-mode isolation transformer includes a plurality of isolated primary windings. Each of the plurality of isolated primary windings can be electrically isolated from others of the isolated primary windings and selectively couplable to a power source of the plurality of power sources. The switch-mode isolation transformer further includes a secondary winding coupled to a load. The apparatus further includes a controller to selectively couple one of the plurality of power sources through a corresponding isolated primary winding, responsive to detecting an adverse condition in another power source of the plurality of power sources. Other methods and systems are also described.