Light-emitting system having a luminous flux control device

A luminous flux control device adapted to be connected to a first solid-state light-emitting component that has an anode and a cathode, one of which is disposed to receive an input voltage, and that has a first forward voltage when driven under a constant current condition, said luminous flux control device comprising:

• a second solid-state light-emitting component having an anode and a cathode, one of which is disposed to receive the input voltage, and having a second forward voltage when driven under a constant current condition;
• and
• a luminous flux control circuit including
• a detection module including a current source and a first instrumentation amplifier, said current source being connected electrically to the other of said anode and said cathode of said second solid-state light-emitting component for providing a constant current through said second solid-state light-emitting component, said first instrumentation amplifier having first and second input terminals that are connected electrically and respectively to said anode and said cathode of said second solid-state light-emitting component for detecting the second forward voltage, said first instrumentation amplifier being operable to generate a first detection voltage that has a magnitude dependent on the second forward voltage detected by said first instrumentation amplifier, and further having an output terminal for outputting the first detection voltage,
• a compensation voltage module connected electrically to said output terminal of said first instrumentation amplifier for receiving the first detection voltage from said first instrumentation amplifier, disposed to receive a first reference voltage and a second reference voltage, and operable to generate a compensation voltage according to the first detection voltage, the first reference voltage, and the second reference voltage received by said compensation voltage module, the compensation voltage having a magnitude related to the second forward voltage, and
• a power control module connected electrically to said compensation voltage module for receiving the compensation voltage from said compensation voltage module, adapted to be connected electrically to the anode and the cathode of the first solid-state light-emitting component for detecting the first forward voltage, and operable to provide a driving current through the first solid-state light-emitting component, the driving current being dependent on the compensation voltage and the first forward voltage received and detected by said power control module and varying according to ambient temperature to stabilize luminous flux of the first solid-state light-emitting component.

A luminous flux control circuit adapted to be connected to a first solid-state light-emitting component that has an anode and a cathode, one of which is disposed to receive an input voltage, and that has a first forward voltage when driven under a constant current condition, and a second solid-state light-emitting component that has an anode and a cathode, one of which is disposed to receive the input voltage, and that has a second forward voltage when driven under a constant current condition, said luminous flux control circuit comprising:

• a detection module including a current source and a first instrumentation amplifier, said current source being adapted to be connected electrically to the other of the anode and the cathode of the second solid-state light-emitting component for providing a constant current through the second solid-state light-emitting component, said first instrumentation amplifier having first and second input terminals that are adapted to be connected electrically and respectively to the anode and the cathode of the second solid-state light-emitting component for detecting the second forward voltage, said first instrumentation amplifier being operable to generate a first detection voltage that has a magnitude dependent on the second forward voltage detected by said first instrumentation amplifier, and further having an output terminal for outputting the first detection voltage;
• a compensation voltage module connected electrically to said output terminal of said first instrumentation amplifier for receiving the first detection voltage from said first instrumentation amplifier, disposed to receive a first reference voltage and a second reference voltage, and operable to generate a compensation voltage according to the first detection voltage, the first reference voltage, and the second reference voltage received by said compensation voltage module, the compensation voltage having a magnitude related to the second forward voltage;
• and
• a power control module connected electrically to said compensation voltage module for receiving the compensation voltage from said compensation voltage module, adapted to be connected electrically to the anode and the cathode of the first solid-state light-emitting component for detecting the first forward voltage, and operable to provide a driving current through the first solid-state light-emitting component, the driving current being dependent on the compensation voltage and the first forward voltage received and detected by said power control module and varying according to ambient temperature to stabilize luminous flux of the first solid-state light-emitting component.