Pump control system with isolated ac voltage detector
AssigneeFranklin Electric Co., Inc.
InventorsRobert Wetekamp, Wei Song
Life of this patent
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Abstract
A pump and a method of operating the pump at a duty-cycle based on the input voltage of the power source energizing the pump. The pump includes at least a first opto-coupler electrically coupled, to the power source. The method includes detecting at least a first opto-coupler state transition; determining a zero-crossing of the input voltage; determining an elapsed time between the zero-crossing and the first opto-coupler state transition; and operating the pump by energizing a power switch at a duty-cycle based on the elapsed time.
Claims19
A method of operating a pump, the method comprising:
- detecting at least a first opto-coupler state transition of a first opto-coupler electrically coupled to a power source coupled to the pump;
- determining a zero-crossing of an input voltage of the power source;
- determining an elapsed time between the zero-crossing and the first opto-coupler state transition;
- and
- operating the pump by energizing a power-switch at a duty-cycle based on the elapsed time.
A pump comprising:
- an opto-coupler electrically coupled, to a power source;
- a first diode connected to block current from the power source to the opto-coupler during a positive half-cycle of an input voltage of the power source until the input voltage exceeds a breakdown voltage of the first diode, the opto-coupler transitioning from a first state to a second state responsive to current flow through the first diode and transitioning from the second state to the first state responsive to the current ceasing to flow through the first diode;
- a power switch electrically coupled to the power source;
- and
- control logic structured to determine an elapsed time between a zero-crossing of the input voltage and the opto-coupler transitioning from the first state to the second state, the control logic further structured to activate the power switch at a duty-cycle corresponding to the elapsed time.
A control circuit comprising:
- a first opto-coupler electrically coupled to a power source;
- a second opto-coupler electrically coupled to the power source;
- a first diode coupled to activate the first opto-coupler in response to an input voltage of the power source exceeding a breakdown voltage of the first diode during a positive half-cycle of the input voltage, the first opto-coupler providing a first output signal responsive to said activation;
- a second diode coupled to activate the second opto-coupler in response to a zero-crossing of the input voltage, the second opto-coupler providing a second output signal responsive to said activation;
- and
- control logic structured to activate a power switch at a duty-cycle based on an elapsed time between the first output signal and the second output signal.
Dependencies are inferred from the claim text.