Dimmer having a microprocessor-controlled power supply

A two-wire load control device for control of a load from a source of AC voltage, comprising:

• a first controllably conductive device adapted to be coupled in series electrical connection between the load and the source of AC voltage;
• a power supply comprising a controllable impedance coupled in series electrical connection with an energy storage element, the power supply operable to provide a DC voltage to the energy storage element, the energy storage element operable to receive energy when the first controllably conductive device is non-conductive;
• and
• a controller powered by the DC voltage of the power supply and coupled to the first controllably conductive device and the controllable impedance for control of the first controllably conductive device and the controllable impedance, respectively;
• wherein the controller is operable to control the controllable impedance to a first impedance value to cause the energy storage element to receive energy at a first rate and to control the controllable impedance to a second impedance value to cause the energy storage element to receive energy at a second rate, wherein the second impedance value is substantially smaller than the first impedance value.

A two-wire load control device for control of a load from a source of AC voltage, comprising:

• a controllably conductive device adapted to be coupled in series electrical connection between the load and the source of AC voltage;
• a power supply comprising an energy storage element, a first energy-receiving circuit for the energy storage element, and a second energy-receiving circuit for the energy storage element, the first energy-receiving circuit allowing the energy storage element to receive energy at a first rate, the second energy-receiving circuit allowing the energy storage element to receive energy at a second rate greater than the first rate, the power supply operable to store energy in the energy storage element when the controllably conductive device is non-conductive, the power supply producing a DC voltage;
• and
• a controller powered by the DC voltage of the power supply, the controller operable to control the controllably conductive device and coupled to the power supply to selectively enable and disable the second energy-receiving circuit.

A two-wire load control device for control of power delivered to an electrical load from a source of AC voltage, comprising:

• a first controllably conductive device adapted to be operatively coupled to the source of AC voltage and to the electrical load for controlling the power delivered to the load;
• a microprocessor coupled to the first controllably conductive device for controlling the first controllably conductive device;
• and
• a power supply adapted to be coupled to the source of AC voltage and coupled to the microprocessor for generating a DC voltage to power the microprocessor, the power supply comprising:
• an energy storage element;
• a second controllably conductive device operatively coupled to the microprocessor and operable to controllably store energy in the energy storage element in response to the microprocessor;
• a low impedance circuit in series electrical connection with the second controllably conductive device;
• and
• a high impedance circuit in parallel electrical connection with the series combination of the low impedance circuit and the second controllably conductive device;
• wherein when the second controllably conductive device is non-conductive, the energy storage element is operable to receive energy through the high impedance circuit, and when the second controllably conductive device is conductive, the energy storage element is operable to receive energy through the low impedance circuit;
• and
• wherein the microprocessor monitors the power supply in order to determine whether the energy storage element is receiving energy through the low impedance circuit.

A power supply for a two-wire load control device for controlling a load from a source of AC voltage, the load control device having a controller, the load control device comprising:

• an energy storage element operable to produce a DC voltage for powering the controller;
• a first energy-receiving circuit for allowing the energy storage element to receive energy at a first rate;
• and
• a second energy-receiving circuit for allowing the energy storage element to receive energy at a second rate greater than the first rate;
• wherein the controller is powered by the DC voltage and is operable to control the power supply to selectively enable and disable the second energy-receiving circuit.

A method for generating a DC voltage in a two-wire load control device for controlling the power delivered from an AC power source to an electrical load, the method comprising the steps of:

• generating the DC voltage across an energy storage element;
• providing the DC voltage to a controller of the load control device;
• and
• controlling with the controller of the load control device the time constant with which the energy storage element charges;
• further wherein the step of controlling the time constant comprises selectively charging the energy storage element with a first time constant and with a second time constant greater than the first rate in response to the controller.

A method for generating a DC voltage in a two-wire load control device, the method comprising the steps of:

• generating the DC voltage across an energy storage element;
• providing the DC voltage to a controller of the load control device;
• selectively allowing the energy storage element to receive energy at a first rate and at a second rate greater than the first rate in response to the controller;
• and
• determining when the DC voltage exceeds a predetermined voltage;
• wherein the step of controlling the rate further comprises allowing the energy storage element to receive energy at the second rate when the DC voltage is below the predetermined voltage.