US 11,871,493 B2
Timing adjustments for accurate zero-crossing determination
Brian Anthony Yokum, New Orleans, LA (US); and Ronald James Gumina, Mandeville, LA (US)
Assigned to LEVITON MANUFACTURING CO., INC., Melville, NY (US)
Filed by Leviton Manufacturing Co., Inc., Melville, NY (US)
Filed on May 25, 2022, as Appl. No. 17/804,005.
Claims priority of provisional application 63/197,013, filed on Jun. 4, 2021.
Prior Publication US 2022/0394835 A1, Dec. 8, 2022
Int. Cl. H05B 47/10 (2020.01)
CPC H05B 47/10 (2020.01) 30 Claims
OG exemplary drawing
 
1. A method of operating an electrical load controller for controlling conduction of a supply of alternating current (AC) power to a load, the supply of AC power having an input AC waveform that is input to the electrical load controller at a line input terminal of the electrical load controller, the input AC waveform comprising zero-crossings between positive and negative half-cycles of the input AC waveform, the method comprising:
obtaining at least one time offset, the at least one time offset representing amounts of time between (i) zero-crossings of an input signal waveform, representative of the input AC waveform, at an input of a zero-crossing detector circuit of the electrical load controller and (ii) corresponding transitions of an output signal from an output of the zero-crossing detector circuit to a microcontroller of the electrical load controller, each of the corresponding transitions corresponding to a respective zero-crossing of the zero-crossings of the input signal waveform and indicating a respective zero-crossing of the input AC waveform; and
determining times of the zero-crossings of the input AC waveform, the determining the times of the zero-crossings of the input AC waveform comprising:
determining times of the corresponding transitions as detected by the microcontroller; and
adjusting the determined times of the corresponding transitions to produce the times of the zero-crossings of the input AC waveform, wherein the adjusting uses the at least one time offset.