| 主权项 |
1. A switched-mode power supply for an output DC voltage supplied to a motorized load, comprising:
a first rectifier circuit configured to generate a first rectified voltage from a first AC voltage, which is an input power source for the switched-mode power supply, an inverter configured to generate a second AC voltage from the first rectified voltage, a transformer having a primary coil electrically coupled to the second AC voltage and a secondary coil generating a third AC voltage, a second rectifier circuit electrically coupled with the secondary coil of the transformer, the second rectifier circuit being configured to generate a second rectified voltage from the third AC voltage, the second rectified voltage correlating to or being at least substantially proportional to the output DC voltage, a monitoring circuit configured to shut off the inverter when at least one of the second rectified voltage and the output DC voltage exceeds a predetermined first threshold, thereby disabling the inverter during idle intervals of the motorized load, at least one capacitor electrically coupled to the second rectifier circuit and disposed between the second rectified voltage and ground, the at least one capacitor configured to discharge when the inverter is switched off until a voltage of the at least one capacitor falls below a predetermined second threshold that is less than the first threshold, thereby causing the monitoring circuit to turn on the inverter, and a voltage divider having a first resistor and a second resistor, the voltage divider being electrically coupled with the second rectified voltage, and wherein the monitoring circuit is configured to switch off the inverter when the voltage at a middle point of the voltage divider exceeds a predetermined third threshold that correlates with the first threshold, wherein the voltage divider is disposed between the output DC voltage or the second rectifier circuit and ground, wherein the middle point of the voltage divider is electrically coupled with a first terminal of a three-terminal component that is configured to conductively connect its second and third terminals with each other when the voltage at the first terminal exceeds a voltage threshold that correlates with the third threshold, and wherein the conductive connection of the second and third terminals causes the inverter to be switched off, and wherein the monitoring circuit further comprises:
a first sub-circuit comprising the voltage divider and a second sub-circuit coupled with the inverter and galvanically decoupled from the first sub-circuit, the second sub-circuit being configured to switch off the inverter under control of the first sub-circuit when the first sub-circuit detects that the first threshold has been exceeded, andan optical coupler that optically connects the first and second sub-circuits at least when the first threshold has been exceeded. |
