Electronic pressure gauge for automatically controlling the fluid pressure of a controlled device with a predetermined range

• US 5,831,171 A
• Filed: 04/28/1997
• Issued: 11/03/1998
• Est. Priority Date: 04/28/1997
• Status: Expired due to Fees

• Current Assignee: Tien-Tsai Huang
• Original Assignee: Tien-Tsai Huang
• Inventors: Huang, Tien-Tsai
• Primary Examiner(s): Dombroske, George M.
• Assistant Examiner(s): FELBER, JOSEPH LEON
• Application Number:
  US08/845,850
• Time in Patent Office: 554 Days
• Field of Search: 137/487.5, 137/505, 73/753
• US Class Current: 73/753
• CPC Class Codes: G01L 19/00 Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve

Abstract

An electronic pressure gauge including a housing, a fluid pressure converter for converting the pressure of the test fluid into a voltage, an electronic low pressure point setting device for setting the desired low pressure point, an electronic high pressure point setting device for setting the desired high pressure point, an electronic low pressure point comparator for comparing the set low pressure point with the voltage of the fluid converter, an electronic high pressure point comparator for comparing the voltage of the fluid converter with the set high pressure point, and a control signal output device adapted to provide different output signals subject to the comparison result of the electronic low pressure point comparator and the electronic high pressure point comparator.

Claims

1. An electronic pressure gauge comprising:

a housing having a fluid input port adapted for receiving the fluid to be measured;

a fluid pressure converter mounted in said housing and adapted to convert the pressure of the fluid into a voltage;

an electronic low pressure point setting device mounted in said housing and adapted for setting a predetermined low pressure point and providing a voltage output corresponding to the set low pressure point;

an electronic high pressure point setting device mounted in said housing and adapted for setting a predetermined high pressure point and providing a voltage output corresponding to the set high pressure point;

an electronic low pressure point comparator mounted in said housing and adapted to receive the output voltage of said fluid pressure converter and the output voltage of said electronic low pressure point setting device and to compare both output voltages, said electronic low pressure point comparator providing a first output signal when the output voltage of said fluid pressure converter is lower than the output voltage of said electronic low pressure point setting device, or a second output signal when the output voltage of said fluid pressure converter is equal to or higher than the output voltage of said electronic low pressure point setting device;

an electronic high pressure point comparator mounted in said housing and adapted to receive the output voltage of said fluid pressure converter and the output voltage of said electronic high pressure point setting device and to compare both output voltages, said electronic high pressure point comparator providing a third output signal when the output voltage of said fluid pressure converter is lower than the output voltage of said electronic high pressure point setting device, or a fourth output signal when the output voltage of said fluid pressure converter is equal to or higher than the output voltage of said electronic high pressure point setting device;

voltage to digital converter means adapted to convert the output voltages of said fluid pressure converter, said electronic low pressure point setting device and said electronic high pressure point setting device into corresponding digital signals;

display means adapted to indicate the digital signals from said voltage to digital converter; and

a control signal output device having a first input end adapted to receive the output signal of said electronic low pressure comparator, a second input end adapted to receive the output signal of said electronic high pressure comparator, and an output end adapted for providing an output signal to a fluid supply control system to control its operation;

wherein said control signal output device provides a fifth output signal when the pressure of the fluid is lower than the set high pressure point of said electronic high pressure point setting device; and

wherein when the fluid pressure is zero, said control signal output device provides said fifth output signal to turn on said fluid supply control system;

when the fluid pressure surpasses the set low pressure point, said control signal output device keeps providing said fifth output signal to said fluid supply control system;

when the fluid pressure surpasses the set high pressure point, said control signal output device provides a sixth output signal to turn off said fluid supply control system;

when the fluid pressure drops below the set high pressure point, said control signal output device keeps providing said sixth output signal to said fluid supply control system, and therefore said fluid supply control system does no work;

when the fluid pressure drops below the set low pressure point, said control signal output device provides said fifth output signal to said fluid supply control system, causing it to be turned on.

2. The electronic pressure gauge of claim 1 wherein said electronic low pressure setting device and said electronic high pressure setting device comprise a respective variable resistor for setting the desired low pressure point and the desired high pressure point.

3. The electronic pressure gauge of claim 1 wherein said electronic low pressure point comparator and said electronic high pressure point comparator comprise a respective operational amplifier.

4. The electronic pressure gauge of claim 1 wherein said control signal output device comprises a flip-flop having a reset end connected to the first input end of said control signal output device and a set end connected to the second input end of said control signal output device.