Abstract: The present invention discloses an arc extinguishing switch, including a mechanical switch and a first electric branch connected in parallel with a first contact branch of the mechanical switch, the first electric branch includes a first controllable unidirectional turn-on subbranch and a second controllable unidirectional turn-on subbranch, the first controllable unidirectional turn-on subbranch and the second controllable unidirectional turn-on subbranch are respectively controlled by two thyristors to be turned on in AC positive and negative periods correspondingly and share a first capacitor connected in series with the two thyristors. The invention further discloses a switching method using the arc extinguishing switch. In the invention, the high power requirement for the thyristor in the arc extinguishing switch and the product cost are lowered, and it is avoided that the mechanical switch is bypassed when the short-circuit failure occurs on the thyristor.

Abstract: A bridgeless PFC circuit is provided. A low-frequency bridge leg includes a first diode and a second diode connected in series; a three-port network includes a switch tube and an inductor; a lightning and surge protection bridge leg includes a third diode and a fourth diode connected in series; a capacitor is connected between terminals of the low-frequency bridge leg, and between terminals of the lightning and surge protection bridge leg; a common terminal of the first and second diodes is connected to a terminal of an AC power, and a common terminal of the third and fourth diodes is connected to the other terminal; and the three-port network has two ports with the capacitor connected therebetween, and another port connected to the common terminal of the third and fourth diodes. Thus, EMI performance and efficiency can be improved and costs of the whole circuit can be lowered.

Abstract: The present invention discloses an arc extinguishing switch, including a mechanical switch and a first electric branch connected in parallel with a first contact branch of the mechanical switch, the first electric branch includes a first controllable unidirectional turn-on subbranch and a second controllable unidirectional turn-on subbranch, the first controllable unidirectional turn-on subbranch and the second controllable unidirectional turn-on subbranch are respectively controlled by two thyristors to be turned on in AC positive and negative periods correspondingly and share a first capacitor connected in series with the two thyristors. The invention further discloses a switching method using the arc extinguishing switch. In the invention, the high power requirement for the thyristor in the arc extinguishing switch and the product cost are lowered, and it is avoided that the mechanical switch is bypassed when the short-circuit failure occurs on the thyristor.