Electronic switch having an in-line power supply
First Claim
1. A two-wire electronic switch for controlling the power delivered from an AC power source to an electrical load, the electronic switch comprising:
- a latching relay adapted to be coupled in series electrical connection between the source and the load, the latching relay arranged to conduct a load current through the load when the relay is conductive;
a controller configured to control the relay to be conductive and non-conductive to turn the load on and off, respectively;
an output capacitor arranged to develop a DC supply voltage for powering the controller; and
an in-line power supply coupled in series electrical connection with the relay, the in-line power supply further coupled to the output capacitor for generating the DC supply voltage across the output capacitor when the relay is conductive, the power supply configured to conduct the load current through the output capacitor for at least a portion of a line cycle of the AC power source when the relay is conductive;
wherein the relay is rendered non-conductive in response to an over-temperature condition in the electronic switch.
1 Assignment
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Accused Products
Abstract
A two-wire smart load control device, such as an electronic switch, for controlling the power delivered from a power source to an electrical load comprises a relay for conducting a load current through the load and an in-line power supply coupled in series with the relay for generating a supply voltage across a capacitor when the relay is conductive. The power supply controls when the capacitor charges asynchronously with respect to the frequency of the source. The capacitor conducts the load current for at least a portion of a line cycle of the source when the relay is conductive. The load control device also comprises a bidirectional semiconductor switch, which is controlled to minimize the inrush current conducted through the relay. The bidirectional semiconductor switch is rendered conductive in response to an over-current condition in the capacitor of the power supply, and the relay is rendered non-conductive in response to an over-temperature condition in the power supply.
41 Citations
21 Claims
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1. A two-wire electronic switch for controlling the power delivered from an AC power source to an electrical load, the electronic switch comprising:
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a latching relay adapted to be coupled in series electrical connection between the source and the load, the latching relay arranged to conduct a load current through the load when the relay is conductive; a controller configured to control the relay to be conductive and non-conductive to turn the load on and off, respectively; an output capacitor arranged to develop a DC supply voltage for powering the controller; and an in-line power supply coupled in series electrical connection with the relay, the in-line power supply further coupled to the output capacitor for generating the DC supply voltage across the output capacitor when the relay is conductive, the power supply configured to conduct the load current through the output capacitor for at least a portion of a line cycle of the AC power source when the relay is conductive; wherein the relay is rendered non-conductive in response to an over-temperature condition in the electronic switch. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A two-wire electronic switch for controlling the power delivered from an AC power source to an electrical load, the electronic switch comprising:
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a latching relay adapted to be coupled in series electrical connection between the source and the load for turning the load on and off; a first bidirectional semiconductor switch coupled in parallel electrical connection with the relay, the first bidirectional semiconductor switch comprising a control input; a controller configured to turn on the load by first rendering the first bidirectional semiconductor switch conductive and then rendering the relay conductive, the controller configured to turn off the load by first rendering the relay non-conductive and then rendering the first bidirectional semiconductor switch non-conductive; an output capacitor arranged to develop a DC supply voltage for powering the controller; and an in-line power supply coupled in series electrical connection with the relay, the first bidirectional semiconductor switch being electrically connected in parallel with the series combination of the relay and the power supply, the in-line power supply being coupled to the output capacitor for generating the DC supply voltage across the output capacitor when the relay is conductive, the power supply being configured to conduct the load current through the output capacitor for at least a portion of a line cycle of the AC power source when the relay is conductive; wherein the first bidirectional semiconductor switch is rendered conductive in response to an over-current condition in the output capacitor of the power supply. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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21. A two-wire electronic switch for controlling the power delivered from an AC power source to an electrical load, the electronic switch comprising:
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a latching relay adapted to be coupled in series electrical connection between the source and the load for turning the load on and off; a first bidirectional semiconductor switch coupled in parallel electrical connection with the relay, the first bidirectional semiconductor switch comprising a control input; a controller configured to turn on the load by first rendering the first bidirectional semiconductor switch conductive and then rendering the relay conductive, the controller configured to turn off the load by first rendering the relay non-conductive and then rendering the first bidirectional semiconductor switch non-conductive; an output capacitor arranged to develop a DC supply voltage for powering the controller; and an in-line power supply coupled in series electrical connection with the relay, the first bidirectional semiconductor switch being electrically connected in parallel with the series combination of the relay and the power supply, the in-line power supply being coupled to the output capacitor for generating the DC supply voltage across the output capacitor when the relay is conductive, the power supply comprising a second bidirectional semiconductor switch electrically connected in series with the relay and in parallel with the output capacitor, the power supply being configured to render the second bidirectional semiconductor switch non-conductive to charge the output capacitor when the relay is conductive; wherein the first bidirectional semiconductor switch is rendered conductive in response to an over-current condition in the output capacitor of the power supply, and the relay is rendered non-conductive in response to an over-temperature condition in the power supply.
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Specification