Non-metallic liquid tilt switch and circuitry

• US 5,751,074 A
• Filed: 09/08/1995
• Issued: 05/12/1998
• Est. Priority Date: 09/08/1995
• Status: Expired due to Fees

• Current Assignee: Edward B Prior & Associates
• Original Assignee: Edward B Prior & Associates
• Inventors: Lazo, Luis A., Prior, John E., Prior, Edward B., Caristi, Anthony J.
• Primary Examiner(s): SCOTT, JAMES R
• Application Number:
  US08/525,958
• Time in Patent Office: 977 Days
• Field of Search: 200/61.47, 200/182-236, 200/190, 340/440-693, 307/112, 307/125, 219/250
• US Class Current: 307/118
• CPC Class Codes: H01H 29/002 Inertia switches
• CPC Class Codes: H01H 29/22 wherein contact is made and broken between liquid and solid

Abstract

An electrical switch sensitive to an externally applied inertial and gravitational force, having an enclosure with a closed space; a conductive fluid filing a first portion of the space and a non-conductive medium filling a second portion of the space, the conductive fluid and the non-conductive medium having differing densities; at least two electrodes in communication with the space; an electrical circuit coupled the contacts and having electrical connections for connection with a power source and a load, having a semiconductor switching device, which is responsive to a current through the contacts, a current through the contacts causing the semiconductor switching device to change in conductivity. An externally applied force, e.g., gravity or inertial force, causes the conductive fluid to move within the enclosure with respect to the contacts, altering a current through the contacts, and thereby changing a conducting state of the semiconductor switching device. The switch resides within a housing, containing both the enclosure and the electrical circuit.

Claims

1. An electrical switching circuit, sensitive to an externally applied inertial and gravitational force, comprising:

a liquid switch having an enclosed space, a non-metallic conductive fluid filling a first portion of said space and anon-conductive medium filing a second portion of said space, said conductive fluid and said non-conductive medium having differing densities; and

at least two electrical contacts in communication with said space;

an electrical circuit coupled to at least one of said contacts and having a pair of electrical connections for connection with a power source and a load in series, having a semiconductor switching device, said semiconductor switching device being responsive to a current through said at least one contact, a current through said contacts causing said semiconductor switching device to change conductivity, wherein an externally applied force causes said conductive fluid to move within said liquid switch with respect to said at least one contact, altering a current through said contact, thereby changing a conducting state of said semiconductor switching device to selectively control a current flowing through said load, said current flowing through said load being substantially greater than a current through said electrical contacts, said current flowing through said electrical contacts being derived from said current flowing through said load; and

a common housing, containing said liquid switch and said electrical circuit.

2. The electrical switch according to claim 1, wherein said conductive fluid comprises water.

3. The electrical switch according to claim 1, wherein said conductive fluid comprises an aqueous electrolyte solution.

4. The electrical switch according to claim 3, wherein said conductive fluid further comprises polyethylene glycol.

5. The electrical switch according to claim 2, further comprising a C₁ to C₇ alcohol in an amount sufficient to lower a freezing point of said conductive fluid to below about -10 C.

6. The electrical switch according to claim 1, wherein the externally applied inertial force is a tilting with respect to gravity.

7. The electrical switch according to claim 1, wherein the externally applied inertial force is an acceleration force.

8. The electrical switch according to claim 1, further comprising a pivoted mounting linked to said liquid switch.

9. The electrical switch according to claim 1, further comprising an elongated bimetallic temperature sensitive member linked to said liquid switch, varying an orientation of said liquid switch with temperature.

10. The electrical switch according to claim 1 wherein said semiconductor switching device comprises a silicon controlled rectifier.

11. The electrical switch according to claim 1 wherein said semiconductor switching device comprises a triac.

12. The electrical switch according to claim 1 wherein said semiconducting switching device comprises a MOS device.

13. The electrical switch according to claim 1, wherein said liquid switch comprises a hollow elongated member, said electrodes being proximate to one end of said member, said conductive fluid filling less than about half of said member.

14. The electrical switch according to claim 1, wherein said electrical contacts are formed of a material selected from the group consisting of stainless steel and nickel.

15. The electrical switch according to claim 1, wherein said electrodes each have a conductive surface area greater than about π

dh, wherein d is a minimum cross section distance and h is a length of said electrode.

16. The electrical switch according to claim 1, wherein said electrical circuit further comprises a timing circuit, said timing circuit controlling a temporal relationship between said external force and said change in conductivity.

17. An electrical switch circuit sensitive to an externally applied inertial and gravitational force, comprising:

a liquid switch having an enclosed space, a dielectric fluid having a first dielectric property filling a first portion of said space and a medium having a dielectric property different from said dielectric fluid filling a second portion of said space, said dielectric fluid and said medium having differing

densities, and at least two probes in communication with said space;

an solid state electrical circuit coupled to at least two of said probes, said electrical circuit having an electrical connection for connection with a power source and a load in series, and being responsive to a change in capacitance between said probes due to a change in position of said dielectric fluid with respect to said medium to selectively control a current flowing at an output of said electrical circuit, said current flowing at said output being substantially greater than a current through said probes, said current flowing through said probes being derived from said current flowing through said output.

18. A control system for an electrical system, comprising:

a liquid switch having an enclosed space, a conductive fluid filling a first portion of said space and a non-conductive medium filing a second portion of said space, said conductive fluid and said non-conductive medium having differing densities, said conductive fluid consisting essentially of an ionically conductive non-zero-valent metal composition, and at least two electrical contacts in communication with said space;

an electrical circuit coupled to at least one of said contacts for detecting a state of conduction between said contacts, said electrical circuit having an output, wherein an externally applied force causes said conductive fluid to move within said liquid switch with respect to said at least one contact, altering a conduction between said at least two contacts, to selectively control a current flowing at said output of said electrical circuit;

a housing, containing said enclosure and said electrical circuit; and

a control circuit receiving said output from said electrical circuit and controlling the electrical system based on a said output, a current flowing through said electrical system being substantially greater than a current flowing through said contacts.

19. The control system according to claim 18, wherein said electrical system comprises an iron and said conductive fluid comprises an aqueous solution.

20. The control system according to claim 19, wherein said control circuit determines an inclination state of said iron and controls a heating of said iron based on said inclination state.

21. The control system according to claim 19, wherein said control circuit determines an time-varying acceleration state of said iron and controls a heating of said iron based on said time-varying acceleration state.

22. The control system according to claim 19, wherein said control circuit comprises a timer having an output, and a heating of said iron being controlled based on said output of said timer.