Patent ID: 8427065

Claim:
A driving circuit for light emitting elements comprising a rectifying unit having a first terminal and a second terminal, being connected to an external power source that provides alternating current (AC) power being sinusoidal and having alternating negative and positive segments, inverting the negative segments of the AC power to positive segments and forming a pulsating direct current (DC) voltage; a first constant current unit having a first end and a second end; a first driving transistor comprising a first gate connecting to the second end of the first constant current unit; a first drain connecting to the first terminal of the rectifying unit and the first end of the first constant current unit; and a first source outputting a driving current according to a voltage between the first gate and the first source; a first voltage control unit comprising a first variable resistor having a variable resistance controlling the driving current of the first driving transistor and having a first terminal connecting to the first source; and a second terminal; and a first bias control element controlling the voltage between the first gate and the first source according to the driving current of the first driving transistor and having a first end connecting to the first gate; and a second end connecting to the second terminal of the first variable resistor; and at least one first light emitting element having a first end connecting to the second terminal of the first variable resistor; and a second end connecting to the second terminal of the rectifying unit.