Power supply system for multiple loads and driving system for multiple lamps

A power supply system for driving multiple loads including a first load and a second load, comprising:

• an inverter circuit for converting DC power to AC power to be supplied to said loads;
• and
• a current balancing circuit, comprising:
• a variable impedance circuit coupled to said second load;
• a current sampling circuit for obtaining the current values through said first load and through said second load;
• and
• a comparator circuit with its input terminals coupled to said current sampling circuit and its output terminal coupled to said variable impedance circuit for comparing the current values through said first load and through said second load and selectively outputting a control signal to vary the equivalent impedance of said variable impedance circuit to thereby balance the current values through said first load and through said second load.

A power supply system for multiple loads including a master load and a slave load, comprising:

• a driving circuit for supplying power to said loads;
• and
• a current balancing circuit for balancing the currents passing through said master load and said slave load;
• wherein said current balancing circuit comprising:
• a variable impedance circuit including an impedance device coupled to said slave load, a first transistor and a second transistor with their collectors and emitters respectively coupled to the two ends of said impedance device so that the equivalent impedance of said variable impedance circuit varies when either of said first and second transistors is driven;
• current sampling circuit for obtaining the current values of said master load and said slave load;
• and
• comparator circuit with its input coupled to said current sampling circuit and its output coupled to the bases of said first and said second transistors for comparing the currents passing through said master and slave loads and selectively outputting a control signal to drive said first and second transistors.

A driving system for multiple lamps including a first lamp and a second lamp, comprising:

• an inverter circuit for converting DC power to AC power to be supplied to said first and second lamps;
• and
• a current balancing circuit for balancing the currents passing through said first and second lamps;
• wherein said current balancing circuit comprising:
• a first impedance device coupled to said first lamp;
• a second impedance device coupled to said second lamp;
• a first transistor and a second transistor with their collectors and emitters respectively coupled to the two ends of said first impedance device and with their bases coupled to said second impedance device;
• and
• a third transistor and a forth transistor with their collectors and emitters respectively coupled to the two ends of said second impedance device and with their bases coupled to said first impedance device.

A driving system for multiple lamps including a master lamp and a slave lamp, comprising:

• an inverter circuit for converting DC power to AC power to be supplied to said lamps;
• and
• a current balancing circuit, comprising:
• a variable impedance circuit coupled to said slave lamp;
• a current sampling circuit for obtaining the current values through said master lamp and through said slave lamp;
• and
• a comparator circuit with its input terminals coupled to said current sampling circuit and its output terminal coupled to said variable impedance circuit for comparing the current values through said master lamp and through said slave lamp and selectively outputting a [voltage] control signal to vary the equivalent impedance of said variable impedance circuit to thereby balance the current values through said master lamp and through said slave lamp.