| 摘要 |
PROBLEM TO BE SOLVED: To provide a contactless switch, where the number of rectifier circuits is reduced and the number of components is decreased. SOLUTION: This contactless switch 4 employs a two-way switch DIAC as an auxiliary switching element to drive power thyristors THY1, THY2 which are switching elements of an output stage, and the resistance to voltage can be enhanced by connecting a triac TRIAC and a phototriac PT in series with the two-way switch DIAC. Moreover, capacitors C1, C2 as surge absorbing elements are connected in series, and its connection midpoint is connected to the gate of the auxiliary triac TRIAC. Thus, the auxiliary triac TRIAC is driven by a charge/discharge current of the capacitors C1, C2, when the photo triac PT is turned on.
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