SOLID-STATE VOLTAGE AND FAULT DETECTOR MEANS HAVING INTEGRAL CIRCUIT INTEGRITY INDICATORS

• US 3,639,833 A
• Filed: 05/11/1970
• Issued: 02/01/1972
• Est. Priority Date: 05/11/1970
• Status: Expired due to Term

• Current Assignee: Henry N. Tachick
• Original Assignee: Henry N. Tachick
• Inventors: Tachick, Henry N.
• Primary Examiner(s): Strecker, Gerard R.
• Application Number:
  US05/036,053
• Time in Patent Office: 631 Days
• Field of Search: 324/51,72.5,133
• US Class Current: 324/556
• CPC Class Codes: G01R 19/145 Indicating the presence of current or voltage

Abstract

Solid-state detector circuit and portable circuit housing for safely sensing the presence of a voltage or a fault in a highvoltage electric power distribution system. The apparatus is housed in a unitary case and is provided with interchangeable probes to permit it to be either directly or indirectly coupled to a circuit under test. Integral indicating means are provided for selectively monitoring the integrity of the detector circuit to assure its operability before and after it is used on a highvoltage circuit, thereby affording a safeguard for personnel using information provided by the detector.

Claims

1. Apparatus for detecting the presence or absence of a voltage or a fault in high-voltage underground electric power transmission systems comprising:

a direct current power source, a plural position mode switch having means for selectively positioning said switch tO a first position, a second position, and a neutral position, a first indicator lamp, a second indicator lamp, and a third indicator lamp, apparatus input means including a first terminal, a second terminal, and a third terminal, electrical circuitry responsive to the placement of said mode switch in said first position for applying a current from said power source through a first series circuit (A) including said first indicator lamp (15), and for applying current from said power source to a second series circuit (B) including said second indicator lamp (16) and said first and second terminals, said second series circuit being completed by a currentconducting connection between said first and said second terminals, electrical circuitry responsive to the placement of said mode switch in said second position for applying a current from said power source through said first series circuit (A) including said first indicator lamp (15), and for applying current from said power source to a third series circuit (C) including said third indicator lamp (14), a solid state switching means having a normally open circuit state and an activated closed circuit state, said solid state switching means having an input circuit connected to said first and third terminals and being responsive to a predetermined voltage applied across said first and third terminals to activate said switching means to a closed circuit state thereby to provide a current flow from said power source through said third indicator lamp, whereby the apparatus is operative to indicate the presence or absence of such a predetermined voltage.

2. Apparatus for detecting the presence or absence of a voltage or a fault in high-voltage transmission systems as defined in claim 1 and further including a casing having an elongated upper compartment and a lower compartment depending therefrom, said upper compartment having an open end remote from said lower compartment, said apparatus input means being mounted in said open end, said first, second, and third series circuits, said solid state switching means, said plural position mode switch, and said first, second, and third indicator lamps being mounted in said upper compartment, said power source being mounted in said lower compartment, and means extending from said lower to said upper compartment for electrically interconnecting said power source to said plural position mode switch.

3. Apparatus for detecting the presence or absence of a voltage or a fault in high-voltage transmission systems as defined in claim 2 and wherein said plural position mode switch includes a switch position selector extending exterior of said casing and electrical terminal connections extending interior of said casing.

4. Apparatus for detecting the presence or absence of a voltage or a fault in high-voltage transmission systems as defined in claim 3 and wherein each of said indicator lamps includes means for securing each of said lamps to said casing, each of said means for securing said lamps including signal indicating windows extending exterior of said casing and electrical connection terminals extending interior of said casing.

5. Apparatus for detecting the presence or absence of a voltage or a fault in high-voltage transmission systems as defined in claim 4 and wherein said apparatus input means comprises a multiterminal input jack.

6. Apparatus as defined in claim 1 including a manually operable switch (54) having two fixed contacts (54a and 54b) and a movable contact (54c), one of said fixed contacts (54b) being connected in series with indicator lamp (16) and said power source, thereby to afford a circuit for testing indicator lamp (16) when the movable contact (54c) is in engagement with said one contact (54b).

7. Apparatus as defined in claim 6 including a second manually operable switch (53) having two fixed contacts (53a and 53b) and a movable contact (53c), one of said fixed contacts (53B) being connected in series with said indicator lamp (14) and said power source, thereby to afford a circuit for testing indicator lamp (14) when the movable contact (53c) engages said one contact (53b).