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US 12,069,779 B2Granted
Prediction and recovery of zero-crossing information and selective control signal pulse duration
AssigneeLeviton Manufacturing Co., Inc.
InventorsAnkit Milan Sanghvi, Abhishek D. Golwala, A. M. Sarwar Jahan
Life of this patent
Estimating the term…
Abstract
Operating an electrical load controller includes determining a firing angle at which to fire a switching circuit of the electrical load controller, the firing angle corresponding to a firing delay time. In some aspects, the operating includes selecting a control signal pulse duration between a fixed duration and a variable duration, and controlling the supply of AC power to the load based on the selected control signal pulse duration. In some aspects, the operating includes detecting whether a voltage sag is present in the AC waveform and the selecting is based on determining that voltage sag is present in the AC waveform.
Claims28
An electrical load controller for controlling conduction of a supply of alternating current (AC) power to a load, the electrical load controller comprising:
- a line input terminal and a load output terminal, the line input terminal configured to be electrically coupled to the supply of AC power, and the load output terminal configured to be electrically coupled to the load;
- a switching circuit electrically coupled in series between the line input terminal and the load output terminal, the switching circuit having an ON state in which the switching circuit conducts the supply of AC power to the load, and an OFF state in which the switching circuit does not conduct the supply of AC power to the load, the switching circuit configured to be selectively controlled by varying a control signal to the switching circuit between the ON state and the OFF state;
- and
- a controller configured to perform:
- based on a desired load level setting of the electrical load controller, determining a firing angle, of an alternating current (AC) waveform, at which to fire the switching circuit of the electrical load controller to selectively control the switching circuit to conduct the supply of AC power to the load, the firing angle corresponding to a firing delay time, after zero-crossings of the AC waveform, at which to fire the switching circuit;
- selecting a control signal pulse duration, the control signal pulse duration being a duration of time for the control signal to be held in the ON state to latch the switching circuit to conduct the supply of AC power to the load, wherein the selecting the control signal pulse duration comprises selecting, for the control signal pulse duration, and based on the determined firing angle, between:
- (i) a fixed duration of time that begins at the firing delay time and ends after the fixed duration of time;
- and
- (ii) a variable duration of time that begins at the firing delay time and ends at a preset unlatch time of the AC waveform;
- and
- controlling the supply of AC power to the load based on the selected control signal pulse duration, wherein the controlling holds the control signal in the ON state for the selected control signal pulse duration in selectively controlling the switching circuit to conduct the supply of AC power to the load.
8 more elements
An electrical load controller for controlling conduction of a supply of alternating current (AC) power to a load, the electrical load controller comprising:
- a line input terminal and a load output terminal, the line input terminal configured to be electrically coupled to the supply of AC power, and the load output terminal configured to be electrically coupled to the load;
- a switching circuit electrically coupled in series between the line input terminal and the load output terminal, the switching circuit configured to be selectively controlled by varying a control signal to a switching circuit between an ON state in which the switching circuit conducts the supply of AC power to the load, and an OFF state;
- and
- a controller, the controller configured to perform:
- based on a desired load level setting of the electrical load controller, determining a firing angle, of an alternating current (AC) waveform, at which to fire a switching circuit of the electrical load controller to selectively control the switching circuit to conduct a supply of AC power to a load, the firing angle corresponding to a firing delay time, after zero-crossings of the AC waveform, at which to fire the switching circuit;
- detecting whether a voltage sag is present in the AC waveform;
- selecting a control signal pulse duration, the control signal pulse duration being a duration of time for a control signal to be held in an ON state to latch the switching circuit to conduct the supply of AC power to the load, wherein the selecting the control signal pulse duration comprises selecting, for the control signal pulse duration, and based on the determined firing angle, between:
- (i) a fixed duration of time that begins at the firing delay time and ends after the fixed duration of time;
- and
- (ii) a variable duration of time;
- wherein the selecting is based further on determining that the firing delay time is less than a first threshold delay, and on the detecting whether the voltage sag is present in the AC waveform;
- and
- controlling the supply of AC power to the load based on the selected control signal pulse duration, wherein the controlling holds the control signal in the ON state for the selected control signal pulse duration in selectively controlling the switching circuit to conduct the supply of AC power to the load.
10 more elements
A method of operating an electrical load controller, the method comprising:
- based on a desired load level setting of the electrical load controller, determining a firing angle, of an alternating current (AC) waveform, at which to fire a switching circuit of the electrical load controller to selectively control the switching circuit to conduct a supply of AC power to a load, the firing angle corresponding to a firing delay time, after zero-crossings of the AC waveform, at which to fire the switching circuit;
- selecting a control signal pulse duration, the control signal pulse duration being a duration of time for a control signal to be held in an ON state to latch the switching circuit to conduct the supply of AC power to the load, wherein the selecting the control signal pulse duration comprises selecting, for the control signal pulse duration, and based on the determined firing angle, between:
- (i) a fixed duration of time that begins at the firing delay time and ends after the fixed duration of time;
- and
- (ii) a variable duration of time that begins at the firing delay time and ends at a preset unlatch time of the AC waveform;
- and
- controlling the supply of AC power to the load based on the selected control signal pulse duration, wherein the controlling holds the control signal in the ON state for the selected control signal pulse duration in selectively controlling the switching circuit to conduct the supply of AC power to the load.
4 more elements
Dependencies are inferred from the claim text.