摘要 |
PUMP CONTROL SYSTEM FOR INSTANTLY REVERSING THE DRIVE MOTOR A liquid flow system comprising a bidirectional liquid pump, a bidirectional electric motor coupled to drive the pump, and a liquid flow line having the pump connected therein. The system further comprises a motor control circuit connected to power the motor in either the forward or the reverse direction. The control circuit includes a switch for connecting the motor windings to the power lines, the switch being operable to instantly reverse the power connections when the motor is operating in the forward direction and thereby powering the motor-pump to an instant stop and then immediately powering the motor in the reverse direction. The pump thereby instantly reverses the liquid flow in the flow line and abruptly terminates the flow. To quickly start the flow again in the forward direction later on, a priming loop is connected to the pressure side of the pump, so that the pump is able quickly to develop pump pressure. |