Patent ID: 7638905

Claim:
A circuit that stabilizes voltage supply to an inverter circuit of an LCD apparatus, comprising: two stable modes of operations that include a power-ON mode of operation and a standby-STB mode of operation; the circuit includes a switching transformer within a power supply circuit; the switching transformer includes a first secondary winding and a second secondary winding that have respective first and second winding ratios; the first secondary winding and the second secondary winding respectively include a first output terminal and a second output terminal, with the first output terminal and the second output terminal respectively outputting a first output voltage V Out1 having a first output power-ON mode voltage V out1-ON and a first output standby-STB mode voltage V out1-STB and a second output voltage V Out2 having a second output power-ON mode voltage V out2-ON and a second output standby-STB mode voltage V out2-STB in accordance with the first and second secondary winding ratio of the switching transformer and mode of operation such that the second output voltage value is lower than the first output voltage, and the first output voltage is used for feedback control of said switching transformer; a first diode having an anode connected to the first output terminal; a first regulator integrated circuit (IC) having an input terminal that is connected to a cathode of the first diode, forming a first junction, with the first junction having a first power-ON mode voltage V 1-ON and a first standby-STB voltage V 1-STB for respective power-ON and standby-STB mode of operations; a second diode having an anode connected to an output terminal of the first regulator IC; a second regulator integrated circuit (IC) having an input terminal that is connected to a cathode of the second diode, and having an output terminal coupled to the inverter circuit at a fourth power-ON mode voltage V 4-ON and a fourth standby-STB voltage V 4-STB for respective power-ON and standby-STB mode of operations; a third diode having a cathode connected to the input terminal of the second regulator IC, forming a second junction, with the second junction having a third power-ON mode voltage V 3-ON and a third standby-STB voltage V 3-STB for respective power-ON and standby-STB mode of operations; a fourth diode having an anode connected to the second output terminal and a cathode connected to an anode of the third diode, forming a third junction, with the third junction having a second power-ON mode voltage V 2-ON and a second standby-STB voltage V 2-STB for respective power-ON and standby-STB mode of operations; with the secondary windings ratios set such that during stable modes of operations: i. V Out1 >V Out2 ii. a. V 1-ON >V 1-STB >V 3-ON and V 3-STB >V 4-ON and V 4-STB , and b. V 1-ON >V 2-ON , and c. V 1-STB <V 2-ON iii. V 2-ON >V 2-STB iv. V 2-ON >V 3-ON and V 3-STB >V 4-ON and V 4-STB v. a. V 3-ON and V 3-STB >V 2-STB , and b. V 4-ON and V 4-STB >V 2-STB .