| 摘要 |
PURPOSE:To efficiently control a motor by supplying a gate signal synchronized with once per twice of signals synchronized with the zero volt crossing point of an AC power source to a 3-terminal control element after a motor stop signal is inputted, thereby flowing a half-wave current to the auxiliary winding. CONSTITUTION:A signal (ZVS) synchronized with the zero volt crossing point of an AC power source is measured by a ZVS measuring unit 18, and the output is inputted to a calculator 20. The caluculator 20 calculates as prescribed to control switching circuits 21, 22 of the rear stage. Switching circuits 33, 34 are controlled ON or OFF by the outputs of the circuits 21, 22, and 3-terminal control elements 12, 13 are further controlled. When a motor stop signal is inputted to the calculator 20, a current of one direction is flowed to a main winding 13 and an auxiliary winding 15 synchronously with once per twice of ZVS, thereby braking. Then, a current of one direction is flowed only to the winding 15 synchronously with once per twice of the ZVS, and the braking is further performed. |
