Circuit protection device

• US 4,878,038 A
• Filed: 12/07/1987
• Issued: 10/31/1989
• Est. Priority Date: 12/07/1987
• Status: Expired due to Fees

• Current Assignee: James T. Tsai
• Original Assignee: James T. Tsai
• Inventors: Tsai, James T.
• Primary Examiner(s): Broome, H.
• Application Number:
  US07/129,651
• Time in Patent Office: 694 Days
• Field of Search: 361/106, 338/22 R, 337/102-107, 337/404, 337/377
• US Class Current: 337/107
• CPC Class Codes: H01H 2009/0083 using redundant components, e.g. two pressure tubes for pressure switch
• CPC Class Codes: H01H 37/585 the switch being of the reed switch type
• CPC Class Codes: H01H 61/013 Heating arrangements for operating relays
• CPC Class Codes: H01H 61/02 wherein the thermally-sensitive member is heated indirectly, e.g. resistively, inductively
• CPC Class Codes: H01H 71/14 Electrothermal mechanisms combined with a electro-thermal time delay relay H01H61/002
• CPC Class Codes: H02H 9/026 Current limitation using PTC resistors, i.e. resistors with a large positive temperature coefficient

Abstract

Multiple embodiments of a device suitable for arrangement in a circuit for protection of components in the circuit are disclosed, the device of each embodiment including a temperature responsive electrical regulating component including a conductive polymer or ceramic material having an electrical regulating capability dependent on temperature and at least one series connected switch including trip means also responsive to temperature for opening and closing the circuit in a reliable manner, the device being adapted for connection in the circuit to be protected. The various embodiments include different arrangements of the temperature responsive electrical regulating component and the switch. Certain of the embodiments include a second series connected switch of similar construction. The conductive polymer or ceramic material can be of a variety of types for performing different electrical regulating functions within the circuit.

Claims

1. A device suitable for arrangement in a circuit for protection of components in the circuit, comprising

a temperature responsive electrical regulating means including a conductive polymer means or ceramic means having an electrical regulating capability dependent on temperature,

first switch means arranged in series with the temperature responsive electrical regulating means, the switch means including trip means for opening the circuit and positively terminating current flow in a reliable manner, and

means for connecting the temperature responsive electrical regulating means and first switch means in the circuit,

the trip means of the first switch means comprising and elongated member responsive to temperature for opening the circuit, the conductive polymer or ceramic means of the temperature responsive electrical regulating means being of cylindrical configuration and surrounding the elongated member in spaced apart relation therefrom in order to assure rapid response of the circuit protection device.

21. The circuit protection device of claim 1 wherein the housing is disc shaped and formed from insulation material, the temperature responsive electrical regulating means being in sheet form arranged within the housing adjacent one end of the electrode and in contact with the elongated switch means.

2. A device suitable for arrangement in a circuit for protection of components in the circuit, comprising

a temperature responsive electrical regulating means including a conductive polymer means or ceramic means having an electrical regulating capability dependent on temperature,

first switch means arranged in series with the temperature responsive electrical regulating means, the switch means including trip means for opening the circuit and positively terminating current flow in a reliable manner, and

means for connecting the temperature responsive electrical regulating means and first switch means in the circuit,

the trip means of the first switch means comprising an elongated member arranged in a conductive housing and responsive to temperature for opening the circuit, the conductive polymer or ceramic means being arranged adjacent to and in conductive relation with the housing in order to assure rapid response of the circuit protection device.

3. The circuit protection device of claim 2 further comprising a second switch means of similar construction as the first switch means and arranged in series with the temperature responsive electrical regulating means and with the first switch means, the conductive polymer or ceramic means being arranged between and in conductive relation with the respective housings for the first and second switch means.

4. A device suitable for arrangement in a circuit for protection of components in the circuit, comprising

a temperature responsive electrical regulating means including a conductive polymer means or ceramic means having an electrical regulating capability dependent on temperature,

first switch means arranged in series with the temperature responsive electrical regulating means, the switch means including trip means for opening the circuit and positively terminating current flow in a reliable manner, and

means for connecting the temperature responsive electrical regulating means and first switch means in the circuit,

the trip means of the first switch means comprising a ferrite magnetic switch in order to assure rapid response of the circuit protection device.

5. The circuit protection device of claim 4 further comprising a second switch means of similar construction as the first switch means and arranged in series with the temperature responsive electrical regulating means and with the first switch means, the conductive polymer or ceramic means being arranged between and in conductive relation with the respective housings for the first and second switch means.

6. A device suitable for arrangement in a circuit for protection of components in the circuit, comprising

a temperature responsive electrical regulating means including a conductive polymer means or ceramic means having an electrical regulating capability dependent on temperature,

first switch means arranged in series with the temperature responsive electrical regulating means, the switch means including trip means for opening the circuit and positively terminating current flow in a reliable manner,

means for connecting the temperature responsive electrical regulating means and first switch means in the circuit,

a second switch means of similar construction as the first switch means and arranged in series with the temperature responsive electrical regulating means and with the first switch means.

7. A device suitable for arrangement in a circuit for protection of components in the circuit, comprising

a temperature responsive electrical regulating means including a conductive polymer means or ceramic means having an electrical regulating capability dependent on temperature,

first switch means arranged in series with the temperature responsive electrical regulating means, the switch means including trip means for opening the circuit and positively terminating current flow in a reliable manner, and

means for connecting the temperature responsive electrical regulating means and first switch means in the circuit,

the trip means of the first switch means comprising an elongated member arranged generally coaxially in a cylindrical housing, the temperature responsive electrical regulating means also being arranged within the housing adjacent one end of the elongated member.

8. The circuit protection device of claim 7 wherein the conductive polymer or ceramic means comprises a conductive material suitable for regulating current flow in the circuit in response to temperature.

9. The circuit protection device of claim 7 wherein the conductive polymer or ceramic means comprises a conductive material suitable for regulating electrical power in the primary circuit in response to temperature.

10. The circuit protection device of claim 7 wherein the first switch means also includes automatic reset means.

11. The circuit protection device of claim 7 wherein the housing is formed from insulation material and the temperature responsive electrical regulating means is in contact with the electrodes.

12. The circuit protection device of claim 11 wherein the housing is conductive and further comprising insulating means mounting the temperature responsive electrical regulating means in the housing.

13. The circuit protection device of claim 12 wherein the conductive polymer or ceramic means is formed with opposite conductive surfaces arranged generally perpendicularly to the axis of the housing, one end of the elongated member being fixed in conductive relation with one of the conductive surfaces.

14. A device suitable for arrangement in a circuit for protection of components in the circuit, comprising

first switch means including an elongated member fixed at one end and arranged generally along the axis of a conductive housing, the housing including a contact point, the elongated member being temperature responsive for moving into and out of engagement with the contact point,

a temperature responsive electrical regulating means arranged in series with the first switch means and including a conductive polymer or ceramic means having an electrical regulating capability dependent on temperature, and

means for connecting the temperature responsive electrical regulating means and the first switch means with the circuit whereby the temperature responsive electrical regulating means provides electrical regulation for the circuit and the switch means positively opens and closes the circuit.

15. The circuit protection device of claim 14 wherein the housing is cylindrical and the elongated member is coaxially arranged in spaced apart relation relative to the housing.

16. The circuit protection device of claim 14 wherein the conductive polymer or ceramic means is arranged in abutting and conductive relation with the conductive housing.

17. The circuit protection device of claim 16 further comprising another switch means of similar construction as the one switch means, the second switch means being arranged in series with the temperature responsive electrical regulating means and with the one switch means, the conductive polymer or ceramic means arranged in abutting and conductive relation with the respective housings for the one switch means and the other switch means.

18. The circuit protection device of claim 14 further comprising another switch means of similar construction as the one switch means, the other switch means being arranged in series with the temperature responsive electrical regulating means and with the one switch means.

19. The circuit protection device of claim 14 wherein the temperature responsive electrical regulating means is arranged within the housing adjacent one end of the elongated member and further comprising insulating means for mounting the temperature responsive electrical regulating means within the conductive housing.

20. The circuit protection device of claim 19 wherein the housing is cylindrical and the conductive polymer or ceramic means is formed with opposite conductive surfaces arranged generally perpendicular to the axis of the housing, one end of the elongated member being fixed in conductive relation with one of the conductive surfaces.