一个辅助绕组通常就能给常用的建立在UC384X上的脱机开关电源(SMPS)供电。在其稳态工作期间,此绕组将给主要的脉宽调制(PWM)控制器供电。但是,该控制器总是需要一个小的启动电流,这就会明显降低其工作效率。例如,当SMPS处于极低功耗的等待时期,此时P_(?)=500mW,就会出现这样的情况。对电源功率的任何浪费,例如,对起动网络和控制器的电源功率的任何浪费,都会加大供电线路电源的消耗,从而大大地降低电路的总效率。在较高的供电线路电压下,争取获得可以接受 Auxiliary windings typically power the commonly used off-line switching power supply (SMPS) built on the UC384X. This winding will power the main Pulse Width Modulation (PWM) controller during its steady-state operation. However, the controller always requires a small start-up current, which can significantly reduce its efficiency. For example, when the SMPS is in a very low-power wait period, at which P _ (=) = 500 mW, this can happen. Any waste of power supply, for example any waste of power to the starting network and the controller, will increase the power consumption of the power supply lines, greatly reducing the overall efficiency of the circuit. At higher supply line voltages, gaining access is acceptable