| 摘要 |
<p>A CONTROL CIRCUIT IS PROVIDED FOR AN AUXILIARY POWER SUPPLY IN AN APPARATUS HAVING RUN AND STANDBY MODES OF OPERATION. THE AUXILIARY POWER SUPPLY IS ENERGIZED BY RAW B+ VOLTAGE (RAW B+) AND OPERATES IN A SWITCHED MODE, RESPONSIVE TO A FEEDBACK SIGNAL INDICATIVE OF LOADING. A SWITCHING CIRCUIT (RL, R2, R3, R4, Q2, 16), ALSO ENERGIZED BY THE RAW B+ VOLTAGE, CHANGES THE AUXILIARY POWER SUPPLY BETWEEN OPERATIONAL AND NON OPERATIONALMODES RESPONSIVE TO AN ON/OFF SIGNAL (+23 V-RUN). THE ON/OFF SIGNAL IS INDICATIVE OF THE RUN AND STANDBY MODES OF OPERATION OF THE APPARATUS, FOR EXAMPLE A RUN SUPPLY VOLTAGE GENERATED BY ANOTHER POWER SUPPLY IN THE APPARATUS. THE SWITCHING CIRCUIT INCLUDES A SWITCH OPTICALLY COUPLED TO A VOLTAGE THRESHOLD DETECTOR (Z3). THE SWITCH INTERRUPTS THE FEEDBACK SIGNAL, FOR EXAMPLE BY SHUNTING TO GROUND, IN A MANNER WHICH INHIBITS OPERATION OF THE SWITCHING CONTROLLER DURING THE STANDBY MODE OF OPERATION OF THE APPARATUS. (FIG. 2)</p> |
