A load control device for controlling power delivered from an AC power source to an electrical load may comprise a thyristor, a gate current path, and a control circuit. The control circuit may be configured to control the gate current path to conduct a pulse of gate current through a gate terminal of the thyristor to render the thyristor conductive at a firing time during a half-cycle of the AC power source. The control circuit may operate in a first gate drive mode in which the control circuit renders the gate current path non-conductive after a pulse time period from the firing time. The control circuit may operate in a second gate drive mode in which the control circuit maintains the gate current path conductive after the pulse time period during the half-cycle.

A heating system includes a first plurality of heating elements disposed within an electrostatic chuck and an electrically conductive housing. The heating system further includes one or more switching devices to control temperatures output by the first plurality of heating elements. The heating system further includes a converter that is electrically coupled to the one or more switching devices and disposed within the electrically conductive housing. The electrically conductive housing and the first plurality of heating elements are to operate in a radio frequency (RF) environment. A second plurality of elements are to operate outside of the RF environment. The converter is to communicate with a controller outside of the RF environment via a non-conductive communication link. The controller is to receive a process recipe and is to control the first plurality of heating elements and the second plurality of elements substantially simultaneously based on the process recipe.

A method includes generating, based on a process recipe, a first electrical control signal by a processing device external to a particular radio frequency (RF) environment. The method further includes converting the first electrical control signal into an alternative control signal, transmitting the alternative control signal to a converter within the particular RF environment over a non-conductive communication link, and converting the alternative control signal into a second electrical control signal by the converter. The method further includes controlling a first plurality of elements via one or more switching devices using the second electrical control signal. The method further includes generating, based on the process recipe, a third signal by the processing device and controlling a second plurality of elements disposed outside of the RF environment using the third signal. The first plurality of elements and the second plurality of elements are controlled substantially simultaneously based on the process recipe.

A matrix converter system operating in current control mode is provided. The matrix converter includes a switching matrix coupled between a low voltage side and a high voltage side, wherein the matrix converter is coupled at its low voltage side to a generator for receiving an input power including an input current and transforming the input power into an output power at its high voltage side, wherein a load is coupled to the high voltage side. The control system includes a load observer and a model predictive controller (MPC). The load observer is configured to estimate a load current that flows to the load from the high voltage side of the matrix converter as a function of a switching state of the switching matrix, an output voltage output at the high voltage side of the matrix converter, and the input current. The MPC is configured to select the switching state of the switching matrix to meet one or more control objectives defined by minimization of a multi-objective function that tracks the output voltage and the input current using the estimated load current.

A load control device for controlling the amount of power delivered from an AC power source to an electrical load is operable to conduct enough current through a thyristor of a connected dimmer switch to exceed rated latching and holding currents of the thyristor. The load control device comprises a controllable-load circuit operable to conduct a controllable-load current through the thyristor of the dimmer switch. The load control device disables the controllable-load circuit when the phase-control voltage received from the dimmer switch is a reverse phase-control waveform. When the phase-control voltage received from the dimmer switch is a forward phase-control waveform, the load control device is operable to decrease the magnitude of the controllable-load current so as to conduct only enough current as is required in order to exceed rated latching and holding currents of the thyristor.

The present invention relates to a power tool monitored by tracking a motor current and control methods thereof. The present invention is mainly about a microprocessor electrically connected to a motor through a drive unit and a current detecting-and-converting module. The microprocessor receives an AC synchronizing signal, and sends a first control signal to the drive unit according to the AC synchronizing signal to drive the motor. The current detecting-and-converting module detects and converts the motor current and output to the microprocessor, thereby the microprocessor detects a per unit time current which is converted into a corresponding pressure value, and then the microprocessor sends a second control signal to the drive unit according to the pressure value to control the operation status of the motor. By detecting and tracking the per unit time current, the purpose of load monitoring and motor protection can be achieved.

A load control device for controlling power delivered from an AC power source to an electrical load may comprise a thyristor, a gate current path, and a control circuit. The control circuit may be configured to control the gate current path to conduct a pulse of gate current through a gate terminal of the thyristor to render the thyristor conductive at a firing time during a half-cycle of the AC power source. The control circuit may operate in a first gate drive mode in which the control circuit renders the gate current path non-conductive after a pulse time period from the firing time. The control circuit may operate in a second gate drive mode in which the control circuit maintains the gate current path conductive after the pulse time period during the half-cycle.

A triac driving circuit according to an embodiment of the present disclosure includes a phototriac coupler, a first resistive element, and a second resistive element, which are connected in series to a gate terminal of a triac. A minimum resistance of the first resistive element including tolerance is higher than a maximum resistance of the second resistive element including tolerance.

A triac driving circuit according to an embodiment of the present disclosure includes a phototriac coupler, a first resistive element, and a second resistive element, which are connected in series to the gate terminal of the triac. A minimum resistance of the first resistive element including tolerance is higher than the maximum resistance of the second resistive element including tolerance.

A load control device for controlling the amount of power delivered from an AC power source to an electrical load is operable to conduct enough current through a thyristor of a connected dimmer switch to exceed rated latching and holding currents of the thyristor. The load control device comprises a controllable-load circuit operable to conduct a controllable-load current through the thyristor of the dimmer switch. The load control device disables the controllable-load circuit when the phase-control voltage received from the dimmer switch is a reverse phase-control waveform. When the phase-control voltage received from the dimmer switch is a forward phase-control waveform, the load control device is operable to decrease the magnitude of the controllable-load current so as to conduct only enough current as is required in order to exceed rated latching and holding currents of the thyristor.