| 摘要 |
<p>REGENERATIVE MOTOR CONTROL HAVING IMPROVED FIELD CIRCUIT The field circuit of a regenerative d.c. motor control provides rapid reversal of field current by discharging the inductive energy of the winding back to an alternating current power supply for the field. This is accomplished by firing thyristors in the field circuit late in the half cycles of alternating current by means of an improved firing circuit. The firing circuit includes a pair of firing pulse generators coupled to the thyristors, one for each direction of field current. Each of the pulse generators has a control signal generator for providing a firing control signal to the pulse generator. A bias circuit, such as a voltage divider, is connected to the control signal generator to obtain actuation of the pulse generators and the firing of the thyristors late in the half cycles. The control signal generator also receives the input signal from the regenerative control for increasing the magnitude of the control firing signal beyond that provided by voltage divider to provide motor field current in accordance with the input signal.</p> |
