Pump control system with isolated AC voltage detector

Patent metadata

Field	Value
Publication number	US-10119535-B2
Application number	US-201514602847-A
Country	US
Kind code	B2
Filing date	Jan 22, 2015
Priority date	Oct 14, 2014
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

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.

First claim

What is claimed is:

1. A method of operating a pump based on a voltage of a power source powering the pump, the method comprising:
detecting at least a first opto-coupler state transition of a first opto-coupler electrically coupled to the power source, the power source electrically coupled to a solenoid of the pump, the first opto-coupler having a positive input contact electrically connected to the power source and a negative input contact, and the first opto-coupler transitioning state responsive to current flowing from the power source through the positive input contact to the negative input contact of the first opto-coupler;
detecting a second opto-coupler state transition;
determining a zero-crossing of the voltage of the power source based on the second opto-coupler state transition;
determining an elapsed time between the zero-crossing and the first opto-coupler state transition; and
energizing the solenoid at a duty-cycle based on the elapsed time.

2. A method as in claim 1 , further comprising selecting a first value corresponding to the elapsed time, and basing the duty-cycle on a second value associated with the first value.

3. A method as in claim 1 , wherein the first opto-coupler state transition and the second opto-coupler state transition occur during a positive half-cycle of the voltage.

4. A method as in claim 1 , further comprising blocking a current flow from the power source to the first opto-coupler until a voltage value of the voltage exceeds a breakdown voltage of a first diode.

5. A method as in claim 1 , further comprising blocking a current flow from the power source to the second opto-coupler during a negative half-cycle of the voltage.

6. A method as in claim 1 , wherein the duty-cycle is greater than 40% when the voltage is less than 140 VAC and is less than 40% when the voltage is greater than 140 VAC.

7. A method as in claim 1 , wherein the pump comprises a solenoid pump including a switch-mode power supply powering control logic structured to determine the elapsed time.

8. A method as in claim 1 , wherein the first opto-coupler includes an output contact configured to provide the first output signal.

9. A method as in claim 2 , further comprising applying a gate current to a gate of a triode for alternating current (TRIAC) at a time corresponding to the second value to operate the pump.

10. A pump comprising:
an opto-coupler including an input side having an input positive contact and an input negative contact, the input positive contact adapted to be electrically coupled to a power source having a voltage;
a first diode connected to block current from the power source to the opto-coupler during a positive half-cycle of the voltage of the power source until the 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 input side of the opto-coupler and providing a first output signal responsive to said transition, and transitioning from the second state to the first state responsive to the current ceasing to flow through the input side of the opto-coupler;
a second opto-coupler providing a second output signal responsive to a zero-crossing of the voltage of the power source;
a second diode connected to block current flow from the power source to the second opto-coupler during a negative half-cycle of the voltage;
a solenoid adapted to be electrically coupled to the power source; and
a control logic structured to determine an elapsed time between the first output signal and the second output signal, the control logic further structured to activate the solenoid at a duty-cycle corresponding to the elapsed time.

11. A pump as in claim 10 , further comprising memory having stored therein a first value corresponding to the elapsed time and a second value associated with the first value, wherein the control logic is structured to base the duty-cycle on the second value.

12. A pump as in claim 10 , wherein the duty-cycle is greater than 40% when the voltage is less than 140 VAC and is less than 40% when the voltage is greater than 140 VAC.

13. A pump as in claim 10 , wherein the pump comprises a solenoid pump including a switch-mode power supply powering the control logic.

14. A pump as in claim 10 , wherein the first opto-coupler state transition corresponds to a voltage value of the power source exceeding a threshold amplitude which is greater than zero volts.

15. A pump as in claim 10 , wherein the first opto-coupler includes an output contact configured to provide the first output signal.

16. A pump as in claim 11 , the control logic structured to activate the power switch at a time corresponding to the second value to operate the pump at the duty-cycle.

17. A control circuit comprising:
a first opto-coupler having an input positive contact and an input negative contact, the first opto-coupler changing output state responsive to current flowing from a power source through the input positive contact to the input negative contact;
a second opto-coupler;
a first diode adapted to be electrically coupled to the power source and being electrically coupled to the input positive contact of the first opto-coupler to activate and change the output state of the first opto-coupler in response to a voltage of the power source exceeding a breakdown voltage of the first diode during a positive half-cycle of the 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 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.

18. A control circuit as in claim 17 , wherein the first output signal and the second output signal are isolated from the voltage.

19. A pump as in claim 17 , wherein the first output signal corresponds to a voltage value of the power source exceeding a threshold amplitude.

Assignees

• Franklin Electric Co Inc

Inventors

• Song Wei
• Wetekamp Robert

Classifications

• F04B49/103

  Responsive to speed · CPC title

• F04B49/10

  Other safety measures · CPC title

• G01R31/2837

  Characterising or performance testing, e.g. of frequency response (transient response G01R27/28) · CPC title

• G01R19/175

  Indicating the instants of passage of current or voltage through a given value, e.g. passage through zero · CPC title

• G01R31/42

  AC power supplies · CPC title