TH41271A - Backup power supply for video display devices - Google Patents

Abstract

DC60 (08/01/41) Switched power supply circuit for VIC display device with operating and backup operating modes. The switched power supply control circuit (20) provides a drive pulse (30) at the output point of the operating transformer (T1) at the primary (n1) and secondary (n3,n4) windings for providing the output voltage (Vn,Vn4) for the VIC display device during the operating mode. The operating power switch (Q1) is connected to the primary winding (n1) of the operating transformer (T1) to control the current flow in the primary winding. In response to the drive pulse, the backup transformer (T2) has primary (n51) and secondary (n53) windings for providing the output voltage (Vn3) for the VIC display device during the backup operating mode. The backup power switch (Q51) is connected to the primary winding (n51) of the backup transformer (T2) to control the current flow in the primary winding. The primary winding in response to the drive pulse. The drive pulse from the switched-on power supply control circuit is connected to the operating power switch during the operating mode and to the backup power switch during the backup mode. The switched-on power supply circuit for the VCR display device has operating and backup modes. The switched-on power supply control circuit (20) provides a drive pulse (30) at the output point. The operating transformer (T1) has the primary winding (n1) and secondary windings (n3,n4) to provide the output voltage (Vn,Vn4) for the VCR display device during the operating mode. The operating power switch (Q1) is connected to the primary winding (n1) of the operating transformer (T1) to control the current flow in the primary winding in response to the drive pulse. The backup transformer (T2) has the primary winding (n51) of the backup transformer (T2) to control the current flow in the primary winding in response to the drive pulse. The drive pulse from the switched-on power supply control circuit is Connect the power switch to operate during the working mode and the backup power switch to operate during the backup mode.

Claims (1)

1. Switched power supply circuit for VIC display devices with operating and backup operating modes. The switched power supply circuit consists of: a switched power supply control circuit (20) for providing the drive pulse (30) at the output point; an operating transformer (T1) with primary windings (N1) and secondary windings (n3,n4) for providing the output voltage (Vn3,Vn4) for the VIC display device during the operating mode; a power switch (Q1) connected to the primary winding (n1) of the operating transformer (T1) for controlling the current flow in the primary winding in response to the drive pulse (30); a backup transformer (T2) with primary windings (n51) and secondary windings (n53) for providing the output voltage (Vn3) for the VIC display device during the backup operating mode; The backup power switch (Q51) is connected to the primary coil (n51) of the backup transformer for the drive pulse (30); and the sections (40,R10,R54,R57,R55,R58,Q52,Q53,D55) for the drive pulse (30) to the operating switch (Q1) during the operating mode and to the backup power switch (Q51) during the backup mode (Clause 1, Page 1, Figure 7).