公开(公告)号：US5093755A

公开(公告)日：1992-03-03

申请号：US378258

申请日：1989-07-11

Applicant: Uwe Hartmann ,  Eduard Lohmuller ,  Fritz Ohnemus

Inventor： Uwe Hartmann ,  Eduard Lohmuller ,  Fritz Ohnemus

IPC: G09G1/00 ,  H01J29/07 ,  H04N9/29

CPC classification number: H04N9/29

Abstract: A circuit for demagnetizing a mask in a color picture tube of a television receiver, in which a resistor with positive temperature coefficient is applied to the input alternating current when the receiver is turned on. A bridge rectifier is connected with one terminal, to a first pole of the alternating current source, via the demagnetizing coil that is mounted on the picture tube, and the resistor. The bridge rectifier has another terminal connected to a second pole of the alternating current source. A variable electronic switch interconnects the direct-current output terminals of the bridge rectifier. The variable electronic switch is controlled to continuously decrease current flowing through the demagnetizing coil to zero. For this purpose, a controlling voltage is obtained from a winding in a horizontal-frequency synchronized power-intake stage by flyback rectification. A feedback circuit is connected to a delay network and to the variable electronic switch for opening the latter completely after a time interval determined by the delay network.

Abstract translation: 一种用于对电视接收机的彩色显像管中的掩模进行去磁的电路，其中当接收器接通时，具有正温度系数的电阻器被施加到输入交流电流。 桥式整流器通过安装在显像管上的消磁线圈和电阻器与一个端子连接到交流电源的第一极。 桥式整流器具有连接到交流电源的第二极的另一端子。 可变电子开关将桥式整流器的直流输出端子互连。 可变电子开关被控制以将流过去磁线圈的电流持续减小到零。 为此，通过反激式整流在水平频率同步的动力吸入级中从绕组获得控制电压。 反馈电路连接到延迟网络和可变电子开关，用于在由延迟网络确定的时间间隔之后完全打开后者。