Soft start charging circuit and control method thereof

• Main Authors: FANG XIAOBIN, LIAO YUNTAO, WU JIANFEI, YANG FAN, HU YAJIE
• Format: Patent
• Language: English
• Published: 01.07.2015
• Subjects: AIR-CONDITIONING, AIR-HUMIDIFICATION, VENTILATION, USE OF AIRCURRENTS FOR SCREENING; BLASTING; HEATING; LIGHTING; MECHANICAL ENGINEERING; RANGES; VENTILATING; WEAPONS

The invention provides a soft start charging circuit, which comprises a controller, a first relay, a second relay and a charging resistor, wherein both the first relay and the second relay are electrically connected with the controller; the first relay comprises two contacts namely the first contact and the second contact; the contact of the second relay is connected in series with the charging resistor and then connected in parallel with the first contact; and the contact of the second relay and the second contact are respectively connected in series with different input ends of a three-phase alternating current power supply. The invention further relates to a control method of the soft start charging circuit. According to the soft start charging circuit and the control method thereof, the two relays are respectively placed between any two phases of the input side of the three-phase alternating current power supply, so that operation is simple and convenient. A primary surge current and a secondary surge current are effectively inhibited, and the impact damage of the surge currents to circuit devices is avoided. Meanwhile, the service lives of the relays are prolonged.