Electric arc detector sensor circuit
First Claim
1. An arc detection system for detecting arcing within an alternating current electrical circuit, the electrical circuit conducting a desired alternating current at a primary frequency, the system, comprising:
- a first terminal;
a second terminal;
an inductor electrically coupled between the first and second terminals;
a capacitor electrically coupled to the first terminal;
a transformer including a primary winding magnetically coupled to a secondary winding, the primary winding being electrically coupled between the capacitor and the second terminal; and
an arc monitoring circuit electrically coupled to the secondary winding, the capacitor limiting current at the primary frequency from flowing through the primary winding, and the monitoring circuit detecting currents at frequencies different from the primary frequency and representative of arcing within the electrical circuit.
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Accused Products
Abstract
A sensor arrangement for producing a signal representative of currents having frequencies and/or characteristics associated with arcing within an alternating current electrical system. The arrangement is coupled to an appropriate arc monitoring circuit which determines if the signal produced by the sensor is the result of arcing within the electrical system. One embodiment of the sensor arrangement includes an inductor, and a capacitor connected in series with the primary winding of a transformer. The inductor is typically connected in series with a phase conductor of the electrical system, and the capacitor and the primary winding are connected to the phase conductor in parallel to the inductor. Another embodiment of the sensor arrangement includes a capacitor and the primary winding of a transformer connected in series between the phase conductor of the electrical system and either a ground or neutral conductor of the system. For both embodiments of the sensor arrangement, the secondary windings of the transformers are connected to the arc monitoring circuit.
128 Citations
22 Claims
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1. An arc detection system for detecting arcing within an alternating current electrical circuit, the electrical circuit conducting a desired alternating current at a primary frequency, the system, comprising:
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a first terminal; a second terminal; an inductor electrically coupled between the first and second terminals; a capacitor electrically coupled to the first terminal; a transformer including a primary winding magnetically coupled to a secondary winding, the primary winding being electrically coupled between the capacitor and the second terminal; and an arc monitoring circuit electrically coupled to the secondary winding, the capacitor limiting current at the primary frequency from flowing through the primary winding, and the monitoring circuit detecting currents at frequencies different from the primary frequency and representative of arcing within the electrical circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A sensor useable in an arc detection system of the type for detecting arcing within an alternating current electrical circuit, where the electrical circuit conducts a desired alternating current at a primary frequency, the sensor comprising:
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a first terminal; a second terminal; an inductor having a first impedance at the primary frequency and electrically coupled between the first and second terminals; a capacitor having a second impedance at least 10,000 times the impedance of the inductor at the primary frequency, and electrically coupled to the first terminal; and a transformer having a one-to-one turn ratio and including a primary winding magnetically coupled to a secondary winding, the primary winding having substantially the first impedance at the primary frequency and being electrically coupled between the capacitor and the second terminal such that the capacitor and primary winding are coupled in series between the first and second terminals, and the inductor is coupled between the terminals in parallel with the primary winding and the capacitor. - View Dependent Claims (10, 11)
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12. A method for detecting a signal representative of arcing within an alternating current electrical circuit, the electrical circuit conducting a desired alternating current at a primary frequency, the method comprising the steps of:
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completing the electrical circuit with an inductor; electrically coupling a capacitor in series with a primary winding of a transformer further including a secondary winding; electrically coupling the capacitor and primary winding into the electrical circuit in parallel with the inductor to limit current at the primary frequency from flowing through the primary winding; and monitoring signals produced by the secondary winding to detect currents at frequencies different from the primary frequency and representative of arcing within the electrical circuit. - View Dependent Claims (13, 14, 15, 16, 17)
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18. An arc detection system for detecting arcing within an alternating voltage electrical circuit including a phase conductor and a reference voltage conductor such as a ground conductor or a neutral conductor, the voltage on the phase conductor alternating between maximum and minimum voltages at a primary frequency, the system comprising:
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a capacitor; a transformer including a primary winding magnetically coupled to a secondary winding, the primary winding being electrically coupled in series with the capacitor, and the primary winding and capacitor being electrically coupled between the phase conductor and the reference voltage conductor; and an arc monitoring circuit electrically coupled to the secondary winding, the capacitor limiting current at the primary frequency from flowing through the primary winding, and the monitoring circuit detecting currents at frequencies different from the primary frequency and representative of arcing within the electrical circuit. - View Dependent Claims (19, 20, 21, 22)
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Specification