Data bus test instrument having a tri-colored LED and indicating continuity, voltage and polarity
First Claim
1. An instrument for testing an electrical circuit, said instrument indicating (1) the presence of data bus signals in a circuit, (2) whether such data bus signals are of a low speed or a high speed nature, (3) continuity of a circuit, (4) voltage in a circuit, and (5) the polarity of a DC voltage in a circuit, said instrument comprising:
- first (24) and second (26) terminals connectable to the electrical circuit to be tested;
a first circuit leg (A) comprising a first junction (28), a second junction (30), and a third junction (32), wherein said first junction (28) is connected to one of said terminals, and wherein said third junction (32) is connected to the other of said terminals;
ballast means (40) connecting said first (28) and second (30) junctions, said ballast means (40) including voltage indicator means for indicating the voltage of said circuit being tested;
a tri-color LED (38) connected between said second (30) and third (32) junctions;
a second circuit leg (B) connecting a fourth junction (54) to said first circuit leg (A), said second circuit leg (B) including a first unidirectional conductor (50) having a certain resistance and being connected between said fourth (54) and said second (30) junctions, said first conductor (50) permitting electrical current to flow only in a direction from said fourth junction (54) to said second junction (30), and a second unidirectional conductor (52) having a certain resistance and being connected between said fourth junction (54) and said third junction (32), said second conductor (52) being operable to permit electrical current to flow only in a direction from said fourth junction (54) to said third junction (32); and
a third circuit leg (C) including a switch (22) and a battery (64), said switch (22) serially connecting said battery (64) to said first junction (28), and with said battery (64) also being connected to said fourth junction (54).
1 Assignment
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Accused Products
Abstract
A hand-held instrument for testing wire circuits. A tricolor light emitting diode is utilized to indicate the existence of a signal in a data bus. The diode displays different light signals to indicate the presence of either alternating or direct current, the polarity of a direct current, and continuity in a circuit. Voltage in the circuit is indicated by a variation in glow intensity of an incandescent lamp. The instrument is adapted for servicing and troubleshooting circuitry on board commercial aircraft, including both data bus circuits and other alternating and direct current circuits.
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Citations
5 Claims
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1. An instrument for testing an electrical circuit, said instrument indicating (1) the presence of data bus signals in a circuit, (2) whether such data bus signals are of a low speed or a high speed nature, (3) continuity of a circuit, (4) voltage in a circuit, and (5) the polarity of a DC voltage in a circuit, said instrument comprising:
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first (24) and second (26) terminals connectable to the electrical circuit to be tested; a first circuit leg (A) comprising a first junction (28), a second junction (30), and a third junction (32), wherein said first junction (28) is connected to one of said terminals, and wherein said third junction (32) is connected to the other of said terminals; ballast means (40) connecting said first (28) and second (30) junctions, said ballast means (40) including voltage indicator means for indicating the voltage of said circuit being tested; a tri-color LED (38) connected between said second (30) and third (32) junctions; a second circuit leg (B) connecting a fourth junction (54) to said first circuit leg (A), said second circuit leg (B) including a first unidirectional conductor (50) having a certain resistance and being connected between said fourth (54) and said second (30) junctions, said first conductor (50) permitting electrical current to flow only in a direction from said fourth junction (54) to said second junction (30), and a second unidirectional conductor (52) having a certain resistance and being connected between said fourth junction (54) and said third junction (32), said second conductor (52) being operable to permit electrical current to flow only in a direction from said fourth junction (54) to said third junction (32); and a third circuit leg (C) including a switch (22) and a battery (64), said switch (22) serially connecting said battery (64) to said first junction (28), and with said battery (64) also being connected to said fourth junction (54). - View Dependent Claims (2, 3, 4, 5)
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Specification