Current regulator for modulating brightness levels of solid state lighting

A power converter for providing variable brightness levels for solid state lighting, the power converter couplable to a phase-modulating switch which is couplable to an AC line voltage, the power converter comprising:

• a switching power supply providing a first current;
• and
• an active impedance matching circuit coupled to the switching power supply, the active impedance matching circuit to provide a variable, second current in response to a magnitude of the first current;
• wherein the active impedance matching circuit comprises:
• a first resistor coupled to receive the first current from the switching power supply and provide a first voltage level;
• a second resistor;
• and
• a transistor coupled in series to the second resistor, the transistor responsive to a control voltage to modulate the second, variable current through the second resistor in response to the first voltage level.

A current regulator for providing variable brightness levels for solid state lighting, the current regulator couplable to a phase-modulating switch coupled to an AC line voltage, the current regulator comprising:

• a rectifier;
• a switching power supply providing a first current;
• an impedance matching circuit coupled to the switching power supply and couplable to the phase-modulating switch or to the AC line voltage, the impedance matching circuit to provide a second current through the phase-modulating switch when a magnitude of the first current is below a first predetermined threshold;
• and
• a controller coupled to the switching power supply and couplable to the phase-modulating switch, the controller to determine a root-mean-square (RMS) voltage level provided by the phase-modulating switch from the AC line voltage and to determine a duty cycle for pulse-width current modulation by the switching power supply in response to the comparison of the RMS voltage level to a nominal voltage level.

A current regulator for providing variable brightness levels for a plurality of light emitting diodes, the current regulator couplable to a phase-modulating switch coupled to an AC line voltage, the current regulator comprising:

• a switching power supply providing a first current;
• and
• a controller coupled to the switching power supply and couplable to the phase-modulating switch, the controller to provide power to the plurality of light emitting diodes when the phase-modulating switch is not providing power from the AC line voltage;
• and
• an impedance matching circuit comprising:
• a first resistor coupled to receive the first current from the switching power supply and provide a first voltage level;
• a second resistor;
• and
• a current switch coupled in series to the second resistor, the switch responsive to a control voltage to modulate the second current through the second resistor in response to the first voltage level.