Circuits for driving light sources

A light source driving circuit for powering a first light source and a second light source by a DC (direct current) voltage, comprising:

• a first control circuitry coupled to said first light source and said second light source;
• and
• a second control circuitry coupled to said first light source and said second light source,
• wherein if said DC voltage is within a first range, then said first control circuitry controls a first switch and said second control circuitry controls a second switch to turn on said first light source and to regulate a current flowing through said first light source, wherein said first switch and said second switch are coupled to said first light source,
• wherein if said DC voltage is within a second range, then said first control circuitry controls a third switch and said second control circuitry controls a fourth switch to turn on said first light source and said second light source and to regulate a current flowing through said first light source and said second light source, wherein said third switch and said fourth switch are coupled to said second light source,
• wherein said first control circuitry and said second control circuitry are both coupled to a first common node which is connected between a cathode of said first light source and an anode of said second light source, and wherein said first control circuitry and said second control circuitry are both coupled to a second common node which is connected to the cathode of said second light source,
• wherein a first portion of said current flowing through said first light source flows through said first switch and a second portion of said current flowing through said first light source flows through said second switch if said first light source is on and said second light source is off,
• wherein a first portion of said current flowing through said first light source and said second light source flows through said third switch and a second portion of said current flowing through said first light source and said second light source flows through said fourth switch if said first light source and said second light source are turned on.