Patent ID: 7411354
Filing Date: 2008-08-12
Classification: H05B,Y02B

Abstract:
1. A feedback and protection circuit of a liquid crystal display panel backlight apparatus, comprising: at least one transformer, having a primary pole winding and a primary winding; a switching switch control circuit, having a PWM controller, and said switching switch control circuit is connected to an input terminal and said primary winding; a feedback and protection control unit, having at least one current signal input terminal, at least one voltage signal input terminal, a first delay control terminal, a second delay control terminal and at least one abnormal status protection signal terminal, and said abnormal status protection signal terminal is connected to said PWM controller; at least one current detection component, connected to the current signal input terminal; at least one voltage detection component, connected to said voltage signal input terminal; and at least one output terminal, connected to said secondary pole winding, a cold cathode fluorescent lamp, said current detection component and said voltage detection component; wherein if said cold cathode fluorescent lamp is open circuited or short circuited, said feedback and protection control unit will produce an abnormal status protection signal to said PWM controller based on a first reference voltage value and a second reference voltage value to stop all outputs from said switching switch control circuit to said LCD panel backlight apparatus.