| 摘要 |
PROBLEM TO BE SOLVED: To reduce a number of the parts of an AC motor drive circuit. SOLUTION: Four thyristors SSR1 to SSR4 combined in a cross-bridge pattern are controlled through a thyristor control circuit. When SSR1 and SSR4 are brought into conduction, an AC motor 1 is started. When SSR1 and SSR4 are turned off, the AC motor is brought into free run. To brake the AC motor, SSR5 is brought into conduction and further SSR1 and SSR4 and SSR2 and SSR3 are alternately brought into conduction at every half cycle of alternating current. As a result, direct-current voltage is applied to the AC motor, which is then brought to a sudden stop. |
