Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A two-wire smart load control device, such as an electronic switch, for controlling the power delivered from a power source to an electrical load comprises a relay for conducting a load current through the load and an in-line power supply coupled in series with the relay for generating a supply voltage across a capacitor when the relay is conductive. The power supply controls when the capacitor charges asynchronously with respect to the frequency of the source. The capacitor conducts the load current for at least a portion of a line cycle of the source when the relay is conductive. The load control device also comprises a bidirectional semiconductor switch, which is controlled to minimize the inrush current conducted through the relay. The bidirectional semiconductor switch is rendered conductive in response to an over-current condition in the capacitor of the power supply, and the relay is rendered non-conductive in response to an over-temperature condition in the power supply.

Abstract: 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.

Abstract: 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.

Abstract: A two-wire smart load control device, such as an electronic switch, for controlling the power delivered from a power source to an electrical load comprises a relay for conducting a load current through the load and an in-line power supply coupled in series with the relay for generating a supply voltage across a capacitor when the relay is conductive. The power supply controls when the capacitor charges asynchronously with respect to the frequency of the source. The capacitor conducts the load current for at least a portion of a line cycle of the source when the relay is conductive. The load control device also comprises a bidirectional semiconductor switch, which is controlled to minimize the inrush current conducted through the relay. The bidirectional semiconductor switch is rendered conductive in response to an over-current condition in the capacitor of the power supply, and the relay is rendered non-conductive in response to an over-temperature condition in the power supply.

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 smart load control device, such as an electronic switch, for controlling the power delivered from a power source to an electrical load comprises a relay for conducting a load current through the load, a controller for rendering the relay conductive and non-conductive, and an in-line power supply coupled in series with the relay for generating a supply voltage across a capacitor when the relay is conductive. The power supply controls when the capacitor charges asynchronously with respect to the frequency of the source. The capacitor conducts the load current for at least a portion of a line cycle of the source when the relay is conductive. The controller is operable to determine when the magnitude of the supply voltage reaches a maximum supply voltage threshold, and render the relay non-conductive immediately after the supply voltage reaches the maximum supply voltage 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 comprise a bidirectional semiconductor switch having first and second anti-series connected switching transistors (such as, for example, field-effect transistors) that are adapted to be coupled between the source and the load, and are controlled to be conductive and non-conductive in a complementary basis. The bidirectional semiconductor switch is operable to be rendered conductive and to remain conductive independent of the magnitude of a load current conducted through semiconductor switch. The dimmer switch also comprises a drive circuit for rendering the first and second switching transistors conductive and non-conductive each half-cycle on the complementary basis, so as to control the amount of power delivered to the electrical load to a desired amount of power.

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 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 switching circuit can handle a large inrush current, but does not require a neutral connection or a heavy-duty mechanical switch or relay. The switching circuit comprises a mechanical air-gap switch, a first controllably conductive device (e.g., a bidirectional semiconductor switch), and a second controllably conductive device (e.g., a latching relay), which are all adapted to be coupled between an AC power source and an electrical load when the air-gap switch is in a first position. First and second delay circuits control the semiconductor switch and the latching relay to be conductive at different times after the air-gap switch is changed to the first position. Specifically, the semiconductor switch is rendered conductive before the latching relay is rendered conductive, such that the semiconductor switch conducts the large inrush current. The latching relay conducts current from the AC power source to the electrical load after the inrush current has subsided.

Abstract: A dimmer switch for controlling the amount of power delivered to and thus the intensity of a lighting load comprises a visual display operable to provide a visual indication representative of energy savings and usage information. The dimmer switch comprises an intensity adjustment actuator, such as a slider knob or a rotary knob, which may be coupled to a potentiometer for adjusting the amount of power delivered to the lighting load. The potentiometer may comprise a dual potentiometer including a resistive element and a conductive element having a cut. The visual display may comprise a single visual indicator, which may be illuminated a first color, such as green, when the intensity of the lighting load is less than or equal to the eco-level intensity, and illuminated a second different color, such as red, when the intensity of the lighting load is greater than the eco-level intensity.

Abstract: A two-wire switching circuit can handle a large inrush current, but does not require a neutral connection or a heavy-duty mechanical switch or relay. The switching circuit comprises a mechanical air-gap switch and a controllably conductive device, which are coupled in series and are adapted to be coupled between an AC power source and an electrical load when the mechanical switch is in a first position. A first delay circuit is coupled in parallel with the controllably conductive device and in series with the mechanical air-gap switch. A latching circuit, which is responsive to the first delay circuit, is coupled to the controllably conductive device for controlling the controllably conductive device. The first delay circuit causes the latching circuit to control the controllably conductive device to be conductive after a first predetermined time after the mechanical air-gap switch changes to the first position.

Abstract: A two-wire load control device, such as a dimmer, is operable to control the amount of power delivered to an electrical load, such as a magnetic low-voltage (MLV) load, and comprises a bidirectional semiconductor switch, a timing circuit, a trigger circuit having a variable voltage threshold, and a clamp circuit. When a timing voltage signal of the timing circuit exceeds an initial magnitude of the variable voltage threshold, the trigger circuit is operable to render the semiconductor switch conductive, reduce the timing voltage signal to a predetermined magnitude less than the initial magnitude, and to increase the variable voltage threshold to a second magnitude greater than the first magnitude. The clamp circuit limits the magnitude of the timing voltage signal to a clamp magnitude between the initial magnitude and the second magnitude, thereby preventing the timing voltage signal from exceeding the second magnitude.

Abstract: A dimmer switch for controlling the amount of power delivered to and thus the intensity of a lighting load comprises a visual display operable to provide a visual indication representative of energy savings and usage information. The visual display may comprise a single visual indicator or a linear array of visual indicators. The visual display is illuminated in a first manner when the intensity of the lighting load is less than or equal to a predetermined eco-level intensity, and is illuminated in a second manner when the intensity of the lighting load is greater than the eco-level intensity. For example, the single visual indicator may be illuminated a first color, such as green, when the intensity of the lighting load is less than or equal to the eco-level intensity, and illuminated a second different color, such as red, when the intensity of the lighting load is greater than the eco-level intensity.

Abstract: A two-wire switching circuit can handle a large inrush current, but does not require a neutral connection or a heavy-duty mechanical switch or relay. The switching circuit comprises a mechanical air-gap switch, a first controllably conductive device (e.g., a bidirectional semiconductor switch), and a second controllably conductive device (e.g., a latching relay), which are all adapted to be coupled between an AC power source and an electrical load when the air-gap switch is in a first position. First and second delay circuits control the semiconductor switch and the latching relay to be conductive at different times after the air-gap switch is changed to the first position. Specifically, the semiconductor switch is rendered conductive before the latching relay is rendered conductive, such that the semiconductor switch conducts the large inrush current. The latching relay conducts current from the AC power source to the electrical load after the inrush current has subsided.

Abstract: A two-wire switching circuit can handle a large inrush current, but does not require a neutral connection or a heavy-duty mechanical switch or relay. The switching circuit comprises a mechanical air-gap switch and a controllably conductive device, which are coupled in series and are adapted to be coupled between an AC power source and an electrical load when the mechanical switch is in a first position. A first delay circuit is coupled in parallel with the controllably conductive device and in series with the mechanical air-gap switch. A latching circuit, which is responsive to the first delay circuit, is coupled to the controllably conductive device for controlling the controllably conductive device. The first delay circuit causes the latching circuit to control the controllably conductive device to be conductive after a first predetermined time after the mechanical air-gap switch changes to the first position.

Abstract: A dimmer switch for controlling the amount of power delivered to and thus the intensity of a lighting load comprises a visual display operable to provide a visual indication representative of energy savings and usage information. The dimmer switch comprises an intensity adjustment actuator, such as a slider knob or a rotary knob, which may be coupled to a potentiometer for adjusting the amount of power delivered to the lighting load. The potentiometer may comprise a dual potentiometer including a resistive element and a conductive element having a cut. The visual display may comprise a single visual indicator, which may be illuminated a first color, such as green, when the intensity of the lighting load is less than or equal to the eco-level intensity, and illuminated a second different color, such as red, when the intensity of the lighting load is greater than the eco-level intensity.