摘要：【中文】本发明揭示了一种电压变换电路、原边控制电路及原边开关控制方法，所述原边控制电路包括原边开关控制电路，所述原边开关控制电路用于耦接原边开关；所述原边开关控制电路在检测到光耦原边电流小于设定第一阈值时，向所述原边开关发送能控制其导通的控制信号；所述原边开关控制电路在检测到流过所述原边开关的电流的峰值达到设定第二阈值时，向所述原边开关发送能控制其关断的控制信号。本发明提出的电压变换电路、原边控制电路及原边开关控制方法，无需频率振荡器，结构简单，可降低待机状态下电路的功耗。 【EN】The invention discloses a voltage conversion circuit, a primary side control circuit and a primary side switch control method, wherein the primary side control circuit comprises a primary side switch control circuit which is coupled with a primary side switch; when detecting that the primary current of the optocoupler is smaller than a set first threshold value, the primary switch control circuit sends a control signal capable of controlling the conduction of the primary switch to the primary switch; and the primary side switch control circuit sends a control signal capable of controlling the primary side switch to be turned off to the primary side switch when detecting that the peak value of the current flowing through the primary side switch reaches a set second threshold value. The voltage conversion circuit, the primary side control circuit and the primary side switch control method provided by the invention do not need a frequency oscillator, have simple structures and can reduce the power consumption of the circuit in a standby state.