A multiple location dimming system may include a smart dimmer (e.g., a main load control device) and one or more remote dimmers (e.g., accessory devices) for controlling the amount of power delivered to a lighting load. The multiple location dimming system may be installed in place of a multiple location switch system (e.g., having three, four, or more multi-way switches), and may not require a neutral connection at any of the control devices of the multiple location dimming system. The main load control device and the accessory devices of the multiple location dimming system may be configured to display a present intensity level of a lighting load on one or more visual indicators. The accessory devices may have the same or different user interfaces as the main load control device, and may provide additional functionality over that which the main load control device offers.

A multiple location dimming system may include a smart dimmer (e.g., a main load control device) and one or more remote dimmers (e.g., accessory devices) for controlling the amount of power delivered to a lighting load. The multiple location dimming system may be installed in place of a multiple location switch system (e.g., having three, four, or more multi-way switches), and may not require a neutral connection at any of the control devices of the multiple location dimming system. The main load control device and the accessory devices of the multiple location dimming system may be configured to display a present intensity level of a lighting load on one or more visual indicators. The accessory devices may have the same or different user interfaces as the main load control device, and may provide additional functionality over that which the main load control device offers.

A lighting fixture includes a voltage source circuit and a first light module comprising a first current source circuit and a first light emitting diode (LED) light source. The lighting fixture further includes a second light module that includes a second current source circuit and a second LED light source. The voltage source circuit is configured to provide a voltage source output voltage to the first current source circuit and to the second current source circuit. The first current source circuit is configured to provide a first current to the first LED light source. The second current source circuit is configured to provide a second current to the second LED light source. A voltage level of the voltage source output voltage depends on a waveform of a line dimmer output voltage that is provided to the voltage source circuit.

A single fire-wire bi-directional power fetching and dimmer control system, comprising: a dimmer circuit, that includes at least a dimmer driver and two connected bi-directional power electronic components; a single fire-wire bi-directional power fetching module, connected in series between the two bi-directional power electronic components, to perform single fire-wire power fetching when the dimmer circuit is conducting; a high side buck, connected in parallel to the dimmer circuit; and a DC to DC converter, with input end of the converter used for fetching power connected to the single fire-wire bi-directional power fetching module, and the high side buck; and with output end of the converter used for supplying power connected to the dimmer driver of the dimmer circuit. As such, single fire-wire bi-directional dimming can be performed, to raise significantly its range of control, while fetching enough power to drive Wi-Fi and 5G communication.

A control unit controls a bidirectional switch so as to turn the switch from ON to OFF when an amount of time, varying according to a lighting level, passes since a starting point of a half cycle of an AC voltage. When a voltage between both terminals of a capacitive element, connected to a control terminal of the bidirectional switch, becomes equal to or greater than a threshold voltage, the bidirectional switch turns from OFF to ON A first charging/discharging regulator circuit and a second charging/discharging regulator circuit each make a rate of fall of the voltage between both of the terminals of the capacitive element when the bidirectional switch turns from ON to OFF lower than a rate of rise of the voltage between both of the terminals of the capacitive element when the bidirectional switch turns from OFF to ON.

A multiple location dimming system may include a smart dimmer (e.g., a main load control device) and one or more remote dimmers (e.g., accessory devices) for controlling the amount of power delivered to a lighting load. The multiple location dimming system may be installed in place of a multiple location switch system (e.g., having three, four, or more multi-way switches), and may not require a neutral connection at any of the control devices of the multiple location dimming system. The main load control device and the accessory devices of the multiple location dimming system may be configured to display a present intensity level of a lighting load on one or more visual indicators. The accessory devices may have the same or different user interfaces as the main load control device, and may provide additional functionality over that which the main load control device offers.

A load control device coupled between an AC power source and an electrical load may operate in a three-wire mode or a two-wire mode based on whether the load control device is connected to a neutral side of the AC power source. The load control device may further comprise first and second zero-cross detect circuits to be respectively used in the two-wire mode or the three-wire mode, and a neutral wire detect circuit configured to generate a neutral-wire detect signal indicating whether the load control device is connected to the neutral side of the AC power source. A control circuit of the load control device may determine whether the load control device should operate in the two-wire mode or in the three-wire mode in response to the neutral-wire detect signal.

System and method for controlling one or more light emitting diodes. For example, the system includes a bleeder configured to receive a rectified voltage generated by a rectifying bridge, and a dimmer detector configured to receive an input voltage generated by a voltage divider, determine whether or not the rectified voltage is associated with a TRIAC dimmer, and output a control signal to the bleeder. The voltage divider is configured to receive the rectified voltage, and the input voltage indicates a magnitude of the rectified voltage.

A lighting fixture includes a voltage source circuit and a first light module comprising a first current source circuit and a first light emitting diode (LED) light source. The lighting fixture further includes a second light module that includes a second current source circuit and a second LED light source. The voltage source circuit is configured to provide a voltage source output voltage to the first current source circuit and to the second current source circuit. The first current source circuit is configured to provide a first current to the first LED light source. The second current source circuit is configured to provide a second current to the second LED light source. A voltage level of the voltage source output voltage depends on a waveform of a line dimmer output voltage that is provided to the voltage source circuit.

A multiple location dimming system may include a smart dimmer (e.g., a main load control device) and one or more remote dimmers (e.g., accessory devices) for controlling the amount of power delivered to a lighting load. The multiple location dimming system may be installed in place of a multiple location switch system (e.g., having three, four, or more multi-way switches), and may not require a neutral connection at any of the control devices of the multiple location dimming system. The main load control device and the accessory devices of the multiple location dimming system may be configured to display a present intensity level of a lighting load on one or more visual indicators. The accessory devices may have the same or different user interfaces as the main load control device, and may provide additional functionality over that which the main load control device offers.