| 摘要 |
PURPOSE:To contrive to simplify the circuit of the titled device by a method wherein an approach run inverter is started, and after traverse operation is completed, operation is changed over an operation inverter. CONSTITUTION:When an operation command signal is inputted to a microcomputer 7 from an operation input part 8, frequency of the approach run inverter 4 is controlled to make a selected motor 2a-2c to start cushioningly up to a speed N, and frequency f1 corresponding to the speed N is made to be held. Then when the frequency signal f1 coincided with the traverse synchronization signal f0 of the operation inverter 1, traverse operation of the approach run inverter 4 is started. At traverse operation time thereof, when the frequency signal f1 of the approach run inverter 4 coincided with the traverse synchronization signal f0, operation is changed over from the approach run inverter 4 to the operation inverter 1. Accordingly, enhancement of precision of synchronization of the approach run inverter and the operation inverter can be attained by the simple circuit. |
