Systems and methods to control light color temperature during dimming

A power supply, comprising:

• a front end circuit to generate a direct current voltage based on an input voltage;
• a converter circuit to utilize the direct current voltage to generate a first voltage to drive a first light source, a second voltage to drive a second light source, and a sense voltage proportional to a current flowing through the first light source;
• and
• a load current control circuit to control a current flowing through the second light source based at least on the sense voltage, the load current control circuit being configured to control the current flowing through the second light source to cause the first light source and the second light source to operate collaboratively in a dimming function, wherein the load current control circuit is configured to control the current flowing through the second light source based on the sense voltage proportional to a current flowing solely through the first light source, the sense voltage proportional to the current flowing solely through the first light source being determined from at least one sense resistor that is in communication with only the first light source, wherein the load current control circuit comprises a current regulator circuit to control the current flowing through the second light source, the current regulator circuit comprising an operational amplifier, a first resistor coupled to an output of the operational amplifier, a transistor having a gate coupled to the first resistor and a drain coupled to an output of the second light source, a second resistor coupled between a source of the transistor and an input to the operational amplifier, a current sense resistor coupled between the source of the transistor and a negative terminal of the first light source, and a capacitor coupled between the first resistor and the sense resistor.

A method to control light color temperature for at least two light sources, comprising:

• receiving an input voltage from a dimmer;
• converting the input voltage to a direct current voltage;
• generating a first voltage to drive a first light source and a second voltage to drive a second light source based on the direct current voltage;
• and
• controlling a current flowing through the second light source based on a light control setting configured in the dimmer, wherein said controlling the current comprises a load current control circuit configured to control the current flowing through the second light source to cause the first light source and the second light source to operate collaboratively in a dimming function, wherein the load current control circuit is configured to control the current flowing through the second light source based on a sense voltage proportional to a current flowing solely through the first light source, the sense voltage proportional to the current flowing solely through the first light source being determined from at least one sense resistor that is in communication with only the first light source, wherein the load current control circuit comprises a current regulator circuit to control the current flowing through the second light source, the current regulator circuit comprising an operational amplifier, a first resistor coupled to an output of the operational amplifier, a transistor having a gate coupled to the first resistor and a drain coupled to an output of the second light source, a second resistor coupled between a source of the transistor and an input to the operational amplifier, a current sense resistor coupled between the source of the transistor and a negative terminal of the first light source, and a capacitor coupled between the first resistor and the sense resistor.