Pump and pump control circuit apparatus and method

• US 20060204367A1
• Filed: 02/16/2006
• Published: 09/14/2006
• Est. Priority Date: 11/26/2001
• Status: Active Grant

• Current Assignee: Shurflo LLC (Pentair Plc (Ireland))
• Original Assignee: Shurflo LLC (Pentair Plc (Ireland))
• Inventors: Meza, Humberto V., Truong, Quang Minh, Gandhi, Nikhil Jitendra
• Granted Patent: US 8,337,166 B2
• Time in Patent Office: Days
• US Class Current: 417/53
• CPC Class Codes: F04B 2203/0201 Current
• CPC Class Codes: F04B 2203/0208 Power
• CPC Class Codes: F04B 2205/04 Pressure in the outlet chamber
• CPC Class Codes: F04B 43/0054 particularities of the flexible members
• CPC Class Codes: F04B 43/0081 systems, control, safety measures
• CPC Class Codes: F04B 43/04 Pumps having electric drive
• CPC Class Codes: F04B 49/065 and making use of computers

Abstract

A method and apparatus for a pump and a pump control system. The apparatus includes a pressure sensor and a temperature sensor coupled to a pump control system. For the method of the invention, the microcontroller provides a pulse-width modulation control signal to an output power stage in order to selectively control the power provided to the pump.

Claims

1. A method of controlling a pump, the method comprising:

providing power to the pump at a first power level when a pressure in the pump is less than a pressure threshold;

increasing the power to the pump until a current provided to the pump is greater than a low current threshold;

reducing the power to the pump when the current is greater than a high current threshold;

increasing the power to the pump when the current is less than the low current threshold; and

removing the power to the pump when the power to the pump is less than a second power level.

2. The method of claim 1 wherein the power to the pump is a pulse width modulated signal having a duty cycle, and further comprising reducing the duty cycle in order to reduce the power to the pump and increasing the duty cycle in order to increase the power to the pump.

3. The method of claim 1 wherein the first power level is a pulse width modulated signal with a 50 percent duty cycle.

4. The method of claim 1 wherein the high current threshold is 10 amps.

5. The method of claim 1 wherein the low current threshold is 9 amps.

6. The method of claim 1 wherein the second power level is a pulse width modulated signal with a 50 percent duty cycle.

7. The method of claim 1 wherein the pressure threshold is 60 pounds per square inch.

8. A pump control circuit for use with a pump, the circuit comprising:

a pressure switch that senses a pressure inside the pump and closes when the pressure is less than a pressure threshold;

a current sensing circuit that senses a current provided to the pump;

a microcontroller that receives a first signal from the pressure switch and a second signal from the current sensing circuit, the microcontroller programmed to control a speed of the pump with a pulse-width modulation control signal based on the first signal, the second signal, and a calculated pressure; and

an output power stage that receives the pulse-width modulation control signal and controls the application of power to the pump.

9. The pump control circuit of claim 8, wherein the pulse-width modulation control signal has a duty cycle that is reduced in order to reduce the power provided to the pump and that is increased in order to increase the power provided to the pump.

10. A pump control circuit for use with a pump, the circuit comprising:

a pressure switch;

a current sensing circuit;

a microcontroller coupled to the pressure switch and the current sensing circuit,

the microcontroller initiating operating the pump when the pressure switch closes,

the microcontroller controlling power to the pump at a first power level,

the microcontroller increasing the power provided to the pump,

the microcontroller reducing the power provided to the pump when a current provided to the pump is greater than a high current threshold,

the microcontroller increasing the power provided to the pump when the current is less than a low current threshold, and

the microcontroller removing the power provided to the pump when the power is less than a power level threshold.

11. The pump control circuit of claim 10, wherein the pressure switch senses a pressure in an outlet chamber in the pump.

12. The method of claim 10 wherein the power to the pump is provided with a pulse width modulated signal having a duty cycle, and further comprising reducing the duty cycle in order to reduce the power provided to the pump and increasing the duty cycle in order to increase the power provided to the pump.

13. A method of controlling a pump using a pulse-width modulated signal, the method comprising:

providing the pulse-width modulated signal to the pump at a duty cycle less than 100% when a pressure in the pump is less than a pressure threshold;

increasing the duty cycle;

reducing the duty cycle when a current provided to the pump is greater than a high current threshold;

increasing the duty cycle when the current is less than a low current threshold; and

stopping the pump when the duty cycle is less than a duty cycle threshold.

14. A method of controlling a pump, the method comprising:

providing power to the pump at a duty cycle less than 100% when a pressure in the pump is less than a pressure threshold;

increasing the power to the pump;

reducing the power to the pump when the pressure is greater than a high threshold;

increasing the power to the pump when the pressure is less than a low threshold; and

stopping the pump when the power drops below a power threshold.

15. The method of claim 14, wherein power is provided with a pulse-width modulation control signal, and further comprising generating a pulse-width modulation control signal having a duty cycle, and reducing the duty cycle in order to reduce the power provided to the pump and increasing the duty cycle in order to increase the power provided to the pump.