Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
224 words
A bridge amplifier circuit for linearly amplifying a transducer deviation signal produced by variations in resistance of a transducer of a transducer bridge, said transducer bridge including first, second, third, and fourth nodes, said transducer being connected between said second and third nodes, first resistance means being connected between said second and fourth nodes, second resistance means being connected between said fourth node and said first node, third resistance means being connected between said first node and said third node, a power supplying conductor being connected to said fourth node, said bridge amplifier circuit comprising in combination: a. first amplifier means having a positive input, a negative input, and an output coupled to said first, second, and third nodes, respectively, for producing an increased or decreased current through said third resistance means in response to a positive variation in said transducer resistance or a negative variation in said transducer resistance, respectively, said increased or decreased current in said third resistance means acting to maintain said transducer bridge in a balanced voltage condition; and b. constant current maintaining means coupled between said first node and said fourth node for maintaining constant current in said first and second resistance means, whereby current flowing into or out of said bridge amplifier circuit through said first node is linearly related to said variations in resistance of said transducer.
Claim 2
Dependent Claim
224 words
A bridge amplifier circuit for linearly amplifying a transducer deviation signal produced by variations in resistance of a transducer of a transducer bridge, said transducer bridge including first, second, third, and fourth nodes, said transducer being connected between said second and third nodes, first resistance means being connected between said second and fourth nodes, second resistance means being connected between said fourth node and said first node, third resistance means being connected between said first node and said third node, a power supplying conductor being connected to said fourth node, said bridge amplifier circuit comprising in combination: a. first amplifier means having a positive input, a negative input, and an output coupled to said first, second, and third nodes, respectively, for producing an increased or decreased current through said third resistance means in response to a positive variation in said transducer resistance or a negative variation in said transducer resistance, respectively, said increased or decreased current in said third resistance means acting to maintain said transducer bridge in a balanced voltage condition; and b. constant current maintaining means coupled between said first node and said fourth node for maintaining constant current in said first and second resistance means, whereby current flowing into or out of said bridge amplifier circuit through said first node is linearly related to said variations in resistance of said transducer.
Claim 3
Dependent Claim
17 words
The bridge amplifier circuit of claim 1 wherein said first amplifier means includes a first operational amplifier.
Claim 4
Dependent Claim
40 words
The bridge amplifier circuit of claim 2 wherein said first resistance means and said second resistance means are resistors having equal resistance and wherein said third resistance means has a resistance equal to an undeviated resistance value of said transducer.
Claim 5
Dependent Claim
40 words
The bridge amplifier circuit of claim 2 wherein said constant current maintaining means includes low impedance means coupled between said first node and a ground voltage conductor for ensuring that only negligible voltage signals are produced at said first node.
Claim 6
Dependent Claim
51 words
The bridge amplifier circuit of claim 4 wherein said low impedance means includes second amplifier means having a negative input coupled to said first node, a positive input coupled to said ground voltage conductor, and an output coupled to said negative input of said second amplifier means by a feedback element.
Claim 7
Dependent Claim
41 words
The bridge amplifier circuit of claim 5 wherein said second amplifier means includes a second operational amplifier, and wherein said positive and negative inputs of said first amplifier means are directly connected to said first node and said second node, respectively.
Claim 8
Dependent Claim
83 words
The bridge amplifier circuit of claim 2 wherein a constant voltage source having a first polarity terminal and a second polarity terminal has its positive terminal connected to said power supplying conductor and wherein said constant current maintaining means includes second amplifier means having a first input connected to said first node and an output connected to said negative terminal of said constant voltage source for producing voltage variations on said fourth node, substantially equal to any voltage variations on said first node.
Claim 9
Dependent Claim
61 words
The bridge amplifier circuit of claim 7 wherein said second amplifier means includes a second operational amplifier having an output and a positive and a negative input, said negative input of said second operational amplifier being connected to said second polarity terminal of said constant voltage source, said positive input of said second operational amplifier being connected to said first node.
Claim 10
Dependent Claim
24 words
The bridge amplifier circuit of claim 2 wherein said constant current maintaining means includes a constant current source connected to said power supplying conductor.
Claim 11
Dependent Claim
39 words
The bridge amplifier circuit of claim 2 wherein the positive input of said first operational amplifier is directly connected to said first node and the negative input of said first operational amplifier is directly connected to said second node.