Abstract: A two-wire load control device (such as, a dimmer switch or an electronic switch) for controlling power delivered from an AC power source to an electrical load includes a thyristor for controlling the power to the load, a gate coupling circuit electrically coupled to a gate terminal of the thyristor, a control circuit configured to control the thyristor to turn the load on or off, and a power supply configured to conduct current through the electrical load to generate a supply voltage across a capacitor when the thyristor is non-conductive. When the electrical lead is on, the control circuit is configured to maintain the thyristor non-conductive after a beginning of each half-cycle until the magnitude of the supply voltage exceeds a predetermined threshold.

Abstract: A two-wire load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

Abstract: A load control device for controlling the power delivered from an AC power source to an electrical load includes a thyristor, a gate coupling circuit for conducting a gate current through a gate of the thyristor, and a control circuit for controlling the gate coupling circuit to conduct the gate current through a first current path to render the thyristor conductive at a firing time during a half cycle. The gate coupling circuit is able to conduct the gate current through the first current path again after the firing time, but the gate current is not able to be conducted through the gate from a transition time before the end of the half-cycle until approximately the end of the half-cycle. The load current is able to be conducted through a second current path to the electrical load after the transition time until approximately the end of the half-cycle.

Abstract: A two-wire load control device (such as, a dimmer switch) is operable to control the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) and has substantially no minimum load requirement. The load control device includes a bidirectional semiconductor switch (such as thyristor), which may be operable to remain conductive independent of the magnitude of a load current conducted through the thyristor and to conduct the load current to and from the load during a single half-cycle. The dimmer switch comprises a power supply that conducts a charging current through the load in order to generate a supply voltage. The dimmer switch comprises a control circuit that controls a gate coupling circuit for rendering the thyristor conductive each half-cycle. The control circuit may provide a constant gate drive to the thyristor after the thyristor is rendered conductive each half-cycle.

Abstract: A motorized window treatment may provide a low-cost solution for controlling the amount of daylight entering a space through a window. The window treatment may include a covering material (e.g., a cellular shade fabric or a roller shade fabric), a drive assembly for raising and lowering the covering material, and a motor drive unit including a motor configured to drive the drive assembly to raise and lower the covering material. The motorized window treatment may comprise one or more battery packs configured to receive batteries for powering the motor drive unit. The batteries may be located out of view of a user of the motorized window treatment (e.g., in a headrail or in a battery compartment). The motorized window treatment may use various power-saving methods to lengthen the lifetime of the batteries, e.g., to reduce the motor speed to conserve additional battery power and extend the lifetime of the batteries.

Abstract: A motorized window treatment provides a low-cost solution for controlling the amount of daylight entering a space through a window. The window treatment includes a covering material, a drive shaft, at least one lift cord rotatably received around the drive shaft and connected to the covering material, and a motor coupled to the drive shaft for raising and lowering the covering material. The window treatment also includes a spring assist unit for assisting the motor by providing a torque that equals the torque provided by the weight on the cords that lift the covering material at a position midway between fully-open and fully-closed positions, which helps to minimize motor usage and conserve battery life if a battery is used to power the motorized window treatment. The window treatment may comprise a photosensor for measuring the amount of daylight outside the window and temperature sensors for measuring the temperatures inside and outside of the window.

Abstract: A two-wire load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

Abstract: A two-wire load control device (such as, a dimmer switch or an electronic switch) for controlling the power delivered from an AC power source to an electrical load includes a controllably conductive device for controlling the power to the load, a microprocessor operable to generate a control signal that is representative of whether the load should be controlled on or off, a capacitor operable to produce a supply voltage for powering the microprocessor, a power supply that charges the capacitor when the controllably conductive device is non-conductive, and a control circuit that receives the control signal from the microprocessor. The control circuit is operatively coupled to the controllably conductive device for maintaining the controllably conductive device non-conductive after the beginning of each half-cycle until the magnitude of the supply voltage exceeds a predetermined threshold.

Abstract: A two-wire load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

Abstract: A two-wire load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

Abstract: A load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled to the gate of the thyristor, a control circuit, and an RF receiver for receiving an RF signal. The control circuit causes the gate coupling circuit to conduct a gate current to render the thyristor conductive at a firing time during a half cycle of the AC power source, and allows the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle. The thyristor is able to remain conductive independent of the magnitude of a load current conducted through the thyristor and to conduct the load current to and from the electrical load during a single half-cycle.

Abstract: A two-wire load control device (such as, a dimmer switch or an electronic switch) for controlling the power delivered from an AC power source to an electrical load includes a controllably conductive device for controlling the power to the load, a microprocessor operable to generate a control signal that is representative of whether the load should be controlled on or off, a capacitor operable to produce a supply voltage for powering the microprocessor, a power supply that charges the capacitor when the controllably conductive device is non-conductive, and a control circuit that receives the control signal from the microprocessor. The control circuit is operatively coupled to the controllably conductive device for maintaining the controllably conductive device non-conductive after the beginning of each half-cycle until the magnitude of the supply voltage exceeds a predetermined threshold.

Abstract: A two-wire load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

Abstract: A two-wire load control device (such as, a dimmer switch) is operable to control the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) and has substantially no minimum load requirement. The dimmer switch includes a bidirectional semiconductor switch, which is operable to be rendered conductive each half-cycle and to remain conductive independent of the magnitude of a load current conducted through semiconductor switch. The dimmer switch comprises a control circuit that conducts a control current through the load in order to generate a gate drive signal for rendering the bidirectional semiconductor switch conductive and non-conductive each half-cycle. The control circuit may provide a constant gate drive to the bidirectional semiconductor switch after the bidirectional semiconductor switch is rendered conductive each half-cycle.

Abstract: A motorized window treatment system may include a roller tube, a covering material windingly attached to the roller tube, and a drive assembly that may be at least partially disposed within the roller tube. The drive assembly may include a motor having a drive shaft that is elongate along a longitudinal direction and a drive gear attached to the drive shaft such that a toothed portion of the drive gear is cantilevered with respect to the drive shaft. The drive assembly may include a gear assembly having a pair of intermediate gears on opposed sides of the drive gear. Rotation of the drive gear may be transferred through the pair of intermediate gears, a connecting gear, a planetary gear set, a cage, and an idler to the roller tube. Rotation of the roller tube may cause the covering material to move between an open position and a closed position.

Abstract: A two-wire load control device (such as, a dimmer switch) is operable to control the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) and has substantially no minimum load requirement. The load control device includes a bidirectional semiconductor switch (such as a thyristor), which may be operable to remain conductive independent of the magnitude of a load current conducted through semiconductor switch and to conduct the load current to and from the load during a single half-cycle. The dimmer switch comprises a control circuit that conducts a control current through the load in order to generate a gate drive signal for rendering the bidirectional semiconductor switch conductive and non-conductive each half-cycle. The control circuit may provide a constant gate drive to the bidirectional semiconductor switch after the bidirectional semiconductor switch is rendered conductive each half-cycle.

Abstract: A two-wire load control device such as a dimmer switch for controlling the amount of power delivered from an AC power source to an electrical load such as a high-efficiency lighting load may be provided. The load control device may include a bidirectional semiconductor switch coupled between the source and the load and a controller operable to control the bidirectional semiconductor switch. The load control device may also include a front accessible trimming actuator to adjust a low end intensity setting of the load control device. The trimming actuator may be coupled to the controller such that the controller may control the bidirectional semiconductor switch appropriately. Additionally, the trimming actuator may include indicia to help a user readily identify the proper low end intensity setting.

Abstract: A two-wire load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

Abstract: A motorized window treatment controls daylight entering a space through a window and includes a covering material, a drive shaft, lift cords received around the drive shaft and connected to the covering material, and a motor coupled to the drive shaft. It also includes a spring assist unit for the motor providing a torque that equals the torque provided by the weight on the lift cords at a position midway between fully-open and fully-closed positions, minimizing motor usage and conserving battery life. A photosensor for measuring the daylight outside the window and temperature sensors for measuring the temperatures inside and outside of the window may be provided. The position of the covering material is automatically controlled to save energy, or may also be controlled in response to an infrared or radio-frequency remote control.

Abstract: A load control device for control of the power delivered from an AC power source to an electrical load comprises a power supply and a microprocessor that is able to operate the load control device in a low-power mode. The load control device may further comprise at least one visual indicator controlled by the microprocessor to provide visual feedback, where the microprocessor illuminates the visual indicator when the load is on and to turns the visual indicator off when the load is off during the low-power mode. The load control device may comprise a communication circuit coupled to the microprocessor for transmitting and/or receiving digital messages the microprocessor cause the communication circuit to draw less current from the power supply during the low-power mode. The microprocessor may operate in the low-power mode if the magnitude of a voltage of the power supply drops below a predetermined threshold.