Light source driving circuit

A light source driving circuit for driving at least one light-emitting element and controlling a brightness value of said light-emitting element according to a brightness adjusting signal, said light source driving circuit comprising:

• a transformer comprising a primary winding assembly and a secondary winding assembly, wherein said secondary winding assembly is electrically connected to said light-emitting element;
• a switching circuit electrically connected to said primary winding assembly of said transformer;
• a control circuit electrically connected to said switching circuit;
• a brightness adjusting circuit electrically connected to said secondary winding assembly of said transformer and said light-emitting element for detecting an output voltage and/or an output current outputted from said secondary winding assembly and generating a control signal according to the brightness adjusting signal;
• and
• an isolator circuit electrically connected to said brightness adjusting circuit and said control circuit for isolating said primary winding assembly of said transformer from said brightness adjusting circuit, wherein said isolator circuit generates a feedback current according to said control signal and said switching circuit is controlled by said control circuit according to said feedback current,
• wherein as a status of said brightness adjusting signal is changed, a status of said control signal is changed, and a time period of changing said status of said control signal is longer than a time period of changing said status of said brightness adjusting signal.