| 摘要 |
A two speed motor control comprises push buttons that can be activated to start, stop, select a high start of speed or select a low start of speed for the motor. The high and low selector buttons can be used to transfer between high and low speed operation for the motor. Units in the form of AND gates for example can be provided with inputs to establish permissive conditions for a motor start up or speed change operation. These automatically avoid overheating the motor or starting the motor during an inappropriate condition of equipment connected to the motor. Start up and speed selection is achieved without the operator having to verify the existance of appropriate conditions. |
