Battery-powered fault indicator
First Claim
1. A fault indicator operable from a battery for indicating the occurrence of a fault current in a monitored electrical conductor, comprising:
- a housing;
status indicating means within said housing comprising a high impedance display device having at least a pair of display electrodes disposed in operative association with a layer of voltage-responsive light controlling material, the display device providing on the exterior of said housing a first display condition in the absence of an actuating signal applied to said display electrodes, and a second display condition in the presence of an actuating signal applied to said display electrodes;
charge storage means;
switch means rendered conductive upon the occurrence of a fault current in the monitored conductor for momentarily connecting the battery to said charge storage means to develop a charge therein following the fault current; and
circuit means for connecting said charge storage means to said display electrodes whereby said high impedance display device is caused to display said second condition following the fault current.
5 Assignments
0 Petitions
Accused Products
Abstract
A fault indicator operable from an internal battery for indicating the occurrence of a fault current in a monitored electrical conductor of an AC power distribution system. Upon occurrence of a fault current a reed switch in magnetic communication with the monitored conductor momentarily closes to connect the internal battery to a capacitor, which is charged by the battery during the switch closure. The capacitor is connected to the display electrodes of a high impedance liquid crystal display, which displays an "F" to indicate fault occurrence. The fault indication may be reset either by the slow discharge of the capacitor, by discharging the capacitor through a second reed switch manually actuated by a magnetic reset tool from outside the fault indicator housing, or automatically upon restoration of power in the conductor.
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Citations
30 Claims
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1. A fault indicator operable from a battery for indicating the occurrence of a fault current in a monitored electrical conductor, comprising:
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a housing; status indicating means within said housing comprising a high impedance display device having at least a pair of display electrodes disposed in operative association with a layer of voltage-responsive light controlling material, the display device providing on the exterior of said housing a first display condition in the absence of an actuating signal applied to said display electrodes, and a second display condition in the presence of an actuating signal applied to said display electrodes; charge storage means; switch means rendered conductive upon the occurrence of a fault current in the monitored conductor for momentarily connecting the battery to said charge storage means to develop a charge therein following the fault current; and circuit means for connecting said charge storage means to said display electrodes whereby said high impedance display device is caused to display said second condition following the fault current. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A fault indicator operable from a battery for indicating the occurrence of a fault current in a monitored AC conductor, comprising:
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a housing; status indicating means within said housing comprising a high impedance display device having at least one pair of display electrodes disposed in operative association with a layer of voltage-responsive light controlling material, the display device providing on the exterior of said housing a first display condition in the absence of an actuating signal applied to said display electrodes, and a second display condition in the presence of an actuating signal applied to said display electrodes; a capacitor; switch means rendered operative upon the occurrence of a fault current in the monitored conductor for momentarily connecting the battery to said capacitor to establish a charge in said capacitor; and said display electrodes of said display device being connected to said capacitor to condition said display device to said second display condition in the presence of said charge. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A fault indicator operable from a battery for indicating the occurrence of a fault current in a monitored AC conductor, comprising:
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a housing; status indicating means within said housing comprising a high impedance display device having at least one pair of display electrodes disposed in operative association with a layer of voltage-responsive light controlling material, the display device providing on the exterior of said housing a first display condition in the absence of an actuating signal applied to said display electrodes, and a second display condition in the presence of an actuating signal applied to said display electrodes; a capacitor; switch means rendered momentarily conductive by the magnetic field surrounding the monitored conductor upon the occurrence of a fault current in the conductor for momentarily connecting the battery to said capacitor to establish a charge in the capacitor; and said display electrodes of said display device being connected to said capacitor whereby said display device is caused to display said second display condition when said capacitor is charged. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30)
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Specification