Annunciator apparatus for monitoring electrical connections
First Claim
1. In an apparatus for detecting the unauthorized removal of an electrical plug with male contacts wherein said apparatus includes receptacle means with power, neutral and ground terminal means for connection to power, neutral and ground conductors and for receiving the male contacts of the plug and neutral switching means connected to said neutral terminal means for responding to the insertion of the plug into said receptacle means by closing and wherein said apparatus includes annunciator circuit means for indicating the unauthorized removal of the electrical plug from said receptacle meant including input circuit means for producing a transition sensed signal in response to the opening of said neutral switching means when said plug is removed and indicating circuit means for continuously announcing removal of the electrical plug in response to the transition sensed signal, the improvement comprising:
- A. first power supply means connected to the power and neutral conductors for producing a neutral-reference supply voltage for energizing said input circuit means,B. second power supply means connected to the power, neutral and ground conductors for producing a ground-reference supply voltage for energizing said indicating circuit means, andC. isolating signal transfer means for energizing said indicating circuit means in response to the transition sensed signal.
1 Assignment
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Accused Products
Abstract
An annunciator for indicating the removal of an electrical plug from the electrical receptacle. The electrical receptacle includes neutral switching contacts actuated in response to the insertion of a plug into the receptacle. An input circuit in the annunciator apparatus monitors the state of the neutral switching contacts and couples signals produced when a plug is removed to a latching circuit thereby to produce an audible or electrical indication of plug removal. The input Circuit and latching circuit are electrically isolated, and the annunciator detects any attempts to disconnect the apparatus from an external power supply or to remove any internal battery.
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Citations
26 Claims
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1. In an apparatus for detecting the unauthorized removal of an electrical plug with male contacts wherein said apparatus includes receptacle means with power, neutral and ground terminal means for connection to power, neutral and ground conductors and for receiving the male contacts of the plug and neutral switching means connected to said neutral terminal means for responding to the insertion of the plug into said receptacle means by closing and wherein said apparatus includes annunciator circuit means for indicating the unauthorized removal of the electrical plug from said receptacle meant including input circuit means for producing a transition sensed signal in response to the opening of said neutral switching means when said plug is removed and indicating circuit means for continuously announcing removal of the electrical plug in response to the transition sensed signal, the improvement comprising:
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A. first power supply means connected to the power and neutral conductors for producing a neutral-reference supply voltage for energizing said input circuit means, B. second power supply means connected to the power, neutral and ground conductors for producing a ground-reference supply voltage for energizing said indicating circuit means, and C. isolating signal transfer means for energizing said indicating circuit means in response to the transition sensed signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. In an apparatus for detecting the unauthorized removal of an electrical plug wherein said apparatus includes receptacle means with power, neutral and ground terminal means for connection to power, neutral and ground conductors and for receiving the male contacts of the plug and neutral switching means connected to said neutral terminal means for responding to the insertion of the plug into said receptacle means by closing and wherein said apparatus includes annunciator circuit means for indicating the unauthorized removal of the electrical plug from said receptacle means including input circuit means for producing a transition sensed signal in response to the opening of said neutral switching means when a plug is removed and indicating circuit means for continuously announcing removal of the electrical plug in response to the transition sensed signal, the improvement comprising:
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A. first power supply means connectible to the power, and neutral conductors for producing a neutral-reference supply voltage for energizing said input circuit means, B. second power supply means connectible to said power, neutral and ground conductors for producing a ground-reference supply voltage for energizing said indicating circuit means, C. plug connection means for releasably connecting said first and second power supply means to the respective ones of the power, neutral and ground conductors, and D. unidirectional conducting means connected between said ground reference power supply and said neutral reference power supply and connected to said indicating circuit means thereby to initiate a continuous announcing by the indicating circuit means when said plug connection means disconnects from the power, neutral and ground conductors. - View Dependent Claims (21, 22)
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23. In an apparatus for detecting the unauthorized removal of an electrical plug wherein said apparatus includes receptacle means with power, neutral and ground terminal means for connection to power, neutral and ground conductors and for receiving the male contacts of the plug and neutral switching means connected to said neutral terminal means for responding to the insertion of the plug into said receptacle means by closing and wherein said apparatus includes annunciator circuit means for indicating the unauthorized removal of the electrical plug from said receptacle means including input circuit means for producing a transition sensed signal in response to the opening of said neutral switching means when a plug is removed and indicating circuit means for continuously announcing removal of the electrical plug in response to the transition sensed signal, the improvement comprising:
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A. first power supply means connected to said power and neutral conductors for producing a neutral-reference supply voltage for energizing said input circuit means, B. second power supply means connected to said power, neutral and ground conductors for producing a ground-reference supply voltage for energizing said indicating circuit means, and C. independent battery backup means in each of said first and second power supply means for energizing said input circuit means and said indicating circuit means when the power, neutral and ground conductors are deenergized whereby said backup battery means in said first and second power supplies produce voltages with respect to the neutral conductor and the ground conductor respectively. - View Dependent Claims (24, 25, 26)
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Specification