Loading patent…
AssigneeHubbell Incorporated
InventorsThomas S. Nishihira, David A. Blau, John R. Baldwin
Estimating the term…
A method and apparatus for regulating a DC power supply, adaptable for use with a motion sensor switch, by limiting the leakage to ground current of the power supply to comply with U.L. Standards while also enabling the DC power supply to provide a stable DC output voltage which is essentially unaffected by changes in magnitude of the AC supply voltage or changes in ambient temperature. The method and apparatus employs first and second transistors, in which the base and collector of the first transistor and the base and collector of the second transistor are coupled to receive a voltage based on the AC supply voltage, and the emitter of both the first and second transistors are coupled to drive an output circuit of the DC power supply. The emitter of the second transistor is also coupled via a first resistor to the base of the first transistor, and the collector of the second transistor is also coupled via a second resistor to the base of the first transistor. The magnitudes of the first and second resistors are determined such that the leakage to ground current remains substantially constant over a range of magnitudes of the AC supply voltage, and the emitters of the first and second transistors drive the output circuit to provide at a plurality of output terminals a plurality of stable DC output voltages having respective magnitudes which are essentially unaffected by changes in the magnitude of the AC supply voltage. A zener diode can be coupled between the emitters of the first and second transistors to cause the magnitudes of the stable DC output voltages to be essentially unaffected by changes in temperature.
An apparatus for regulating a DC power supply, said DC power supply being adaptable for use with a motion sensor switch and having a power supply input terminal adapted to receive a source AC voltage, at least one power supply output terminal adapted to output at least one DC output voltage, and a ground terminal, said DC power supply generating in response to said source AC voltage a leakage current flowing to said ground terminal, said apparatus comprising:
A method for regulating a DC power supply, said DC power supply being adaptable for use with a motion sensor switch and having a power supply input terminal adapted to receive a source AC voltage, at least one power supply output terminal adapted to output at least one DC output voltage, and a ground terminal, said DC power supply generating in response to said source AC voltage a leakage current flowing to said ground terminal, said method comprising:
An apparatus for regulating a DC power supply, said DC power supply being adaptable for use with a motion sensor switch and having a power supply input terminal adapted to receive a source AC voltage, at least one power supply output terminal adapted to output at least one DC output voltages, and a ground terminal, said DC power supply generating in response to said source AC voltage a leakage current flowing to said ground terminal, said apparatus comprising:
A method for regulating a DC power supply, said DC power supply being adaptable for use with a motion sensor switch and having a power supply input terminal adapted to receive a source AC voltage, at least one power supply output terminal adapted to output at least one DC output voltage, first and second elements coupled between said input and output terminals, and a ground terminal, said DC power supply generating in response to said source AC voltage a leakage current flowing to said ground terminal, said method comprising;
Dependencies are inferred from the claim text.