Pump and pump control circuit apparatus and method

• US 20080152508A1
• Filed: 10/31/2007
• Published: 06/26/2008
• Est. Priority Date: 11/26/2001
• Status: Active Grant

• Current Assignee: Humberto V. Meza, Nikhil Jitendra Gandhi, Quang Minh Troung
• Original Assignee: Humberto V. Meza, Nikhil Jitendra Gandhi, Quang Minh Troung
• Inventors: Troung, Quang Minh, Meza, Humberto V., Gandhi, Nikhil Jitendra
• Granted Patent: US 7,878,766 B2
• Time in Patent Office: Days
• US Class Current: 417/44.2
• 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 pistons integrally formed in a diaphragm and coupled to the diaphragm by convolutes. The convolutes have a bottom surface angled with respect to a top surface of the pistons. The apparatus also includes an outlet port positioned tangentially with respect to the perimeter of an outlet chamber. The apparatus further includes a non-mechanical 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. The control signal is based on the pressure within the pump, the current being provided to the pump, the voltage level of the battery, and the temperature of the pump.

Claims

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

a pressure sensor capable of sensing a pressure in the pump;

a microcontroller coupled to the pressure sensor, the microcontroller programmed to generate a control signal when the sensed pressure is approaching a shut-off pressure; and

an output power stage coupled to receive the control signal from the microcontroller and to provide an increased current to the pump as the sensed pressure approaches the shut-off pressure.

2. The pump control circuit of claim 1, wherein the microcontroller generates a control signal when the sensed pressure is within approximately 2 pounds per square inch of the shut-off pressure.

3. The pump control circuit of claim 1, wherein the increased current provided to the pump is increased by approximately 3 amps within approximately 2 seconds.

4. The pump control circuit of claim 1, wherein the pressure sensor produces a signal representative of changes in the pressure in an outlet chamber in the pump.

5. The pump control circuit of claim 1, wherein the pressure sensor is a silicon semiconductor pressure sensor.

6. The pump control circuit of claim 1, wherein the control signal is a pulse-width modulated control signal having a duty cycle that is increased in order to increase the current supplied to the pump.

7. The pump control circuit of claim 1, wherein an amplifier and filter circuit is coupled between the pressure sensor and the microcontroller.

8. The pump control circuit of claim 7, wherein the amplifier and filter circuit includes a potentiometer used to calibrate the pressure sensor.

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

sensing a pressure in the pump;

comparing the sensed pressure to a shut-off pressure value; and

increasing a current being supplied to the pump when the sensed pressure is approaching the shut-off pressure value.

10. The method of claim 9, and further comprising increasing the current being supplied to the pump when the sensed pressure is within approximately 2 pounds per square inch of the shut-off pressure value.

11. The method of claim 9, and further comprising increasing the current being provided to the pump by approximately 3 amps within approximately 2 seconds.

12. The method of claim 9 wherein sensing a pressure in the pump includes sensing a pressure in an outlet chamber in the pump.

13. The method of claim 9, and further comprising generating a pulse-width modulation control signal based on the sensed pressure.

14. The method of claim 13, and further comprising generating a pulse-width modulation control signal having a duty cycle and increasing the duty cycle in order to increase the current supplied to the pump.

15. The method of claim 13, and further comprising amplifying and filtering the sensed pressure before generating a pulse-width modulation control signal based on the sensed pressure.

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

an electronic pressure sensor that senses actual changes in pressure inside the pump and generates a signal representing the sensed pressure;

a microcontroller coupled to receive the signal from the pressure sensor, the microcontroller programmed to control the speed of the pump based on the sensed pressure by generating a pulse-width modulation control signal; and

an output power stage coupled to receive the control signal from the microcontroller and capable of controlling the application of power to the pump in response to the control signal.

17. The pump control circuit of claim 16, wherein the pressure sensor produces a signal representative of changes in the pressure in an outlet chamber in the pump.

18. The pump control circuit of claim 16, wherein the pulse-width modulation control signal has a duty cycle that is reduced in order to reduce the power supplied to the pump and that is increased in order to increase the power supplied to the pump.

19. The pump control circuit of claim 16, wherein an amplifier and filter circuit is coupled between the pressure sensor and the microprocessor.

20. The pump control circuit of claim 16, wherein the output power stage includes a comparator circuit which determines whether the control signal is a high control signal or a low control signal, and wherein an output of the comparator circuit is positive for a high control signal and negative for a low control signal.

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

sensing an actual pressure inside the pump with an electronic pressure sensor;

generating a pulse-width modulation control signal based on the sensed pressure; and

controlling the application of power to the pump in response to the control signal.

22. The method of claim 21, wherein sensing a pressure in the pump includes sensing a pressure in an outlet chamber in the pump.

23. The method of claim 21, wherein generating a pulse-width modulation control signal based on the sensed pressure includes generating a pulse-width modulation control signal having a duty cycle, and further comprising reducing the duty cycle in order to reduce the power supplied to the pump and increasing the duty cycle in order to increase the power supplied to the pump.

24. The method of claim 21, and further comprising amplifying and filtering the sensed pressure before generating a pulse-width modulation control signal based on the sensed pressure.