Pump and pump control circuit apparatus and method

• US 20080181790A1
• Filed: 10/31/2007
• Published: 07/31/2008
• Est. Priority Date: 11/26/2001
• Status: Active Grant

• Current Assignee: Humberto V. Meza, Nikhil Jitendra Gandhi, Quang Minh Truong
• Original Assignee: Humberto V. Meza, Nikhil Jitendra Gandhi, Quang Minh Truong
• Inventors: Meza, Humberto V., Truong, Quang Minh, Gandhi, Nikhil Jitendra
• Granted Patent: US 8,317,485 B2
• Time in Patent Office: Days
• US Class Current: 417/45
• 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; and

a microcontroller coupled to the pressure sensor and to the pump, the microcontroller operating the pump according to a high-flow mode and a low-flow mode, the high-flow mode having a high-flow current limit value that is not dependent on the sensed pressure, and the low-flow mode having a low-flow current limit value that is less than the high-flow current limit value and that is dependent on the sensed pressure.

2. The pump control circuit of claim 1, wherein the high-flow current limit value is approximately 10 amps.

3. The pump control circuit of claim 1, wherein the pump switches from the low-flow mode to the high-flow mode when the sensed pressure is approximately 28 pounds per square inch.

4. The pump control circuit of claim 1, wherein the pressure sensor senses 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 microcontroller generates a pulse-width modulation control signal having a duty cycle that is reduced in order to reduce power supplied to the pump and that is increased in order to increase power supplied to the pump in response to the high-flow current limit value and the low-flow current limit value.

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; and

operating the pump in a high-flow mode and a low-flow mode based on the sensed pressure, the high-flow mode having a high-flow current limit value that is not dependent on the sensed pressure, and the low-flow mode having a low-flow current limit value that is less than the high-flow current limit value and that is dependent on the sensed pressure.

10. The method of claim 9, and further comprising switching the pump to a high-flow mode having a high-flow current limit value of approximately 10 amps.

11. The method of claim 9, and further comprising switching the pump from the low-flow mode to the high-flow mode when the sensed pressure is approximately 28 pounds per square inch.

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 and at least one of the high-flow current limit value and the low-flow current limit value.

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