Inverter for liquid crystal display
View Patent ↗An inverter for liquid crystal display is disclosed. The inverter for liquid crystal display includes a switching circuit, a transformer, and first and second protective circuits. The switching circuit includes first and second switches and converts a direct current power input into an alternating current power. Each of the first and second switches alternatively performs a turn-on operation and a turn-off operation. The transformer transforms an alternating current power supplied from the switching circuit into a high-voltage alternating current power. The first protective circuit is connected to both terminals of the first switch and protects the first switch during turn-on and turn-off operations of the first switch. The second protective circuit is connected to both terminals of the second switch and protects the second switch during turn-on and turn-off operations of the second switch.
1. An inverter for a liquid crystal display, comprising:
a switching circuit that includes first and second switches and converts a direct current power into an alternating current power, each of the first and second switches alternatively performing a turn-on operation and a turn-off operation;
a transformer that transforms an alternating current power supplied from the switching circuit into a high-voltage alternating current power;
a first protective circuit that is directly connected to both terminals of the first switch and protects the first switch during turn-on and turn-off operations of the first switch; and
a second protective circuit that is directly connected to both terminals of the second switch and protects the second switch during turn-on and turn-off operations of the second switch,
wherein the switching circuit further includes a first stabilization circuit configured to provide a gate terminal of the first switch with a first constant voltage, and a second stabilization circuit connected with the first stabilization circuit and configured to provide a gate terminal of the second switch with a second constant voltage.
2. The inverter for liquid crystal display of claim 1 , wherein the first protective circuit includes a reverse-biased diode and a capacitor each of which is connected to both terminals of the first switch, and a resistor connected to both terminals of the reverse-biased diode.
3. The inverter for liquid crystal display of claim 2 , wherein when the first switch is turned off, the capacitor connected to the reverse-biased diode is charged.
4. The inverter for liquid crystal display of claim 2 , wherein when the first switch is turned on, a current flows in the first switch, a voltage between both terminals of the first switch decreases, and a voltage charged to the capacitor is discharged.
5. The inverter for liquid crystal display of claim 1 , wherein the second protective circuit includes a reverse-biased diode and a capacitor each of which is connected to both terminals of the second switch, and a resistor connected to both terminals of the reverse-biased diode.
6. The inverter for liquid crystal display of claim 5 , wherein when the second switch is turned off, the capacitor connected to the reverse-biased diode is charged.
7. The inverter for liquid crystal display of claim 5 , wherein when the second switch is turned on, a current flows in the second switch, a voltage between both terminals of the second switch decreases, and a voltage charged to the capacitor is discharged.
8. The inverter for liquid crystal display of claim 1 , wherein the first switch is an N-type metal oxide silicon field effect transistor (MOSFET), and the second switch is a P-type MOSFET.
9. The inverter for liquid crystal display of claim 1 , wherein each of the first and second stabilization circuits includes a diode, a zener diode, and one or more resistors.
10. The inverter for liquid crystal display of claim 1 , further comprising a balance capacitor that is connected between the first and second stabilization circuits.
11. The inverter for liquid crystal display of claim 1 , further comprising a direct current blocking capacitor that is connected between a common terminal of the first and second switches and a primary coil of the transformer.
12. The inverter for liquid crystal display of claim 11 , wherein the first stabilization circuit includes an input tenninal to which the direct current power is inputted, a first resistor and a first zenor diode connected in parallel between the input terminal and a node, and a second resistor and a first diode connected in parallel between the gate terminal of the first switch and the node.
13. The inverter for liquid crystal display of claim 12 , wherein the second stabilization circuit includes a third resistor and a second zenor diode connected in parallel between the node and a ground, and a fourth resistor and a second diode connected in parallel between the gate terminal of the second switch and the node.