Circuit testers
First Claim
1. An electrically operable circuit tester for testing circuit integrity in a series-wired electrical circuit, such as a string of Christmas fairy lights powered by domestic mains electricity, the tester comprising or including a housing;
- a pair of matching current sensors associated with the housing, each sensor being adapted to be positioned adjacent a respective one of a pair of wires forming part of the circuit to be tested, such as between or around a pair of wires extending from a fairy light bulb socket, each sensor being electrically connected to a respective one of a matching pair of signal amplifiers to provide a pair of amplified signals, one for each sensor;
a logic gate for receiving amplified signals output from the pair of signal amplifiers and comparing said signals for matching characteristics, the gate providing an output signal to a first display on or in the housing indicative of received and matching signals and a, different, output signal to a second display on or in the housing indicative of received mismatching signals from the amplifiers, the latter thereby indicating a discontinuity in that part of the circuit being tested between the pair of wires, such as by a broken fairy light bulb in that part of the circuit therebetween.
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Accused Products
Abstract
A circuit tester (1) and method of testing the integrity of a series-wired electrical circuit are disclosed, such as a string of Christmas fairy lights powered by domestic means electricity, through the use of a tester comprising a pair of matching AC current sensors (1, 2) adapted to be positioned adjacent to a pair of wires forming part of the circuit to be tested, such as between or around a pair of wires (29, 30) extending from a fairy light bulb socket (31), the tester then feeding the signals to a matching pair of signal amplifiers (3, 4) and thereafter to a logic gate (5) which provides an output signal to a first display (6) indicating the receipt of matching signals and hence a closed circuit between the wires, and in the event of receipt of mismatching signals from the amplifiers a different output signal is sent to a second display (7) which indicates a discontinuity in the circuit between the pair of wires being tested, such as by a broken fairy light bulb in the circuit therebetween.
6 Citations
9 Claims
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1. An electrically operable circuit tester for testing circuit integrity in a series-wired electrical circuit, such as a string of Christmas fairy lights powered by domestic mains electricity, the tester comprising or including a housing;
- a pair of matching current sensors associated with the housing, each sensor being adapted to be positioned adjacent a respective one of a pair of wires forming part of the circuit to be tested, such as between or around a pair of wires extending from a fairy light bulb socket, each sensor being electrically connected to a respective one of a matching pair of signal amplifiers to provide a pair of amplified signals, one for each sensor;
a logic gate for receiving amplified signals output from the pair of signal amplifiers and comparing said signals for matching characteristics, the gate providing an output signal to a first display on or in the housing indicative of received and matching signals and a, different, output signal to a second display on or in the housing indicative of received mismatching signals from the amplifiers, the latter thereby indicating a discontinuity in that part of the circuit being tested between the pair of wires, such as by a broken fairy light bulb in that part of the circuit therebetween. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- a pair of matching current sensors associated with the housing, each sensor being adapted to be positioned adjacent a respective one of a pair of wires forming part of the circuit to be tested, such as between or around a pair of wires extending from a fairy light bulb socket, each sensor being electrically connected to a respective one of a matching pair of signal amplifiers to provide a pair of amplified signals, one for each sensor;
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9. A method of testing a series-wired circuit including the steps of:
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(a) placing two matching AC current field sensors generally symmetrically around or between a pair of wires forming part of the circuit to be tested;
(b) amplifying sensed first and second current signals from both sensors and feeding them to a logic gate to compare both signals and provide a third signal in response thereto, said third signal being HI if, but only if, only one of said first and second signals is low and the other is high; and
(c) subsequently inverting said HI signal to a Low signal to thereafter provide a potential across an electrically powered alarm device, such as a visual display or audio alarm, thereby to indicate a discontinuity in the circuit between the sensors, such as due to a faulty light bulb.
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Specification