| This article introduces a kind of Switched Power Supply suitable for Number control machine. The switched Power Supply meet the requirements of EMI. It has many advantages. For example,high Power Factor,stable and accurate voltages,more groups voltages,the lowest output ripple voltage,multi-layer protection. Based on an overall consideration of various factors,for example: reliability,applicability,cost,the possibility of production,the article adopt single Flyback converter controlled by UC3844. EMI section adopts two-stageEMI composite filter. The electric circuit is easy to demand EMI if the design is reasonable .It is not necessary for more adjustment . The Power Factor Control (PFC) section adopts Boost Active Power Factor Correction (APFC). It is controlled by L6561. L6561 is the IC produced by ST company .The IC is easy to compose the APFC power whose input voltage is wide (AC85V-265V) and loss is low. The IC can drive directly MOS Transistor. L6561 integrates a variety of control functions and has the fewer number of components and has lower power consumption. The switched Power Supply has five output voltage .A group is main control group and the others are supplementary groups.The main circuit adopts single Flyback Circuit adjusted by UC3844.UC3844 is the IC controlled by electric current. The IC can produce signal that drive directly MOS Transistor. The output voltage can be adjusted by PWM Produced by UC3844. The fly back converter circuit is simple and has no shoot-through,so The switched power supply is fit for medium and small power supply. |
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