Remote numerical control soft starter for AC power supply, and control method thereof

The invention discloses a remote numerical control soft starter for an AC power supply. The remote numerical control soft starter comprises a zero crossing detection circuit, a control circuit and a power switch circuit. An input end of the zero crossing detection circuit is connected with an AC power supply phase line input and a null line input, and is used for detecting a zero point position ofan AC sine wave voltage on the AC power supply phase line input, and transmitting the detected zero point position to the control circuit in the form of a zero crossing detection pulse signal. The control circuit is connected with the power switch circuit and is used for starting timing according to a rising edge of the zero crossing detection pulse signal from the zero crossing detection circuitwhen an external enable signal is in an enable state, outputting a silicon controlled starting pulse to the power switch circuit when the timing reaches a timing value, and gradually rising the voltage output by the power switch circuit when the count value is gradually decreased. When the count value is decreased to 0, the control circuit continuously outputs high level signals to the power switch circuit, so that the power switch circuit is in a continuous turned-on state, and the soft start process is completed.