| 摘要 |
PURPOSE:To reduce the loss and to remove a reverse spike voltage of a thyristor by connecting a saturable reactor in series with the thyristor and connecting a diode which blocks a thyristor ON current in parallel with the reactor. CONSTITUTION:A loss reduction and reverse spike voltage removing circuit A in which a diode D is connected in the polarity for blocking a thyristor SCR ON current in parallel with a saturable reactor SaL having a rectangular hysteresis characteristic is connected in series with the thyristor SCR connected with an RC snubber circuit. The current rise at the SCR ON time is suppressed by the reactor SaL to reduce the loss, and the reverse spike voltage at the OFF time is suppressed. Accordingly, the reliability can be improved without using a thyristor having large capacity more than required even when an induction heating power source used for large power and high frequency is used. |
