Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
107 words
A signal-conditioning circuit for use in combination with a transducer of the resistance bridge type, including means for receiving an output signal from a transducer of the resistance bridge type, sensor means for sensing variations in the temperature of the transducer, sensitivity compensation means including gain control means in the path of the transducer output signal responsive to the sensor means for controlling the gain applied to the transducer output signal in dependence upon the temperature of the transducer, and offset compensation means responsive to the sensor means to apply to the transducer output signal a DC offset voltage which varies with the temperature of the transducer.
Claim 2
Dependent Claim
107 words
A signal-conditioning circuit for use in combination with a transducer of the resistance bridge type, including means for receiving an output signal from a transducer of the resistance bridge type, sensor means for sensing variations in the temperature of the transducer, sensitivity compensation means including gain control means in the path of the transducer output signal responsive to the sensor means for controlling the gain applied to the transducer output signal in dependence upon the temperature of the transducer, and offset compensation means responsive to the sensor means to apply to the transducer output signal a DC offset voltage which varies with the temperature of the transducer.
Claim 3
Dependent Claim
87 words
A signal-conditioning circuit as claimed in claim 1, and further including input means for receiving a signal containing both AC and DC components, low-pass filtering means for producing a DC output signal representing the DC component of the transducer output signal, and subtracting means arranged to receive the transducer output signal, and said DC output signal from the filtering means, and to subtract the DC output signal from the transducer output signal to produce an AC output signal representing the AC component of the transducer output signal.
Claim 4
Dependent Claim
17 words
A signal-conditioning circuit as claimed in claim 1, wherein the low-pass filtering means comprises active filtering means.
Claim 5
Dependent Claim
26 words
A signal-conditioning circuit as claimed in claim 3, including manually-adjustable balance control means in the path of the filtered DC component of the transducer output signal.
Claim 6
Dependent Claim
29 words
A signal-conditioning circuit as claimed in claim 1, including balance-control means in the path of the transducer output signal prior to its application to the filtering and subtracting means.
Claim 7
Dependent Claim
30 words
A signal-conditioning circuit as claimed in claim 1, including variable gain-control means in the path of the transducer output signal prior to its application to the filtering and subtracting means.
Claim 8
Dependent Claim
25 words
A signal-conditioning circuit as claimed in claim 1, including variable gain-control means for separately controlling the gain applied to the AC and DC output signals.
Claim 9
Dependent Claim
20 words
A signal-conditioning circuit as claimed in claim 1, wherein the sensor means senses variations in the resistance of the transducer.
Claim 10
Dependent Claim
34 words
A signal-conditioning circuit as claimed in claim 8, wherein the sensor means comprises a temperature-stable sense-resistance which, in use, is connected in series with the transducer and an excitation current source for the transducer.
Claim 11
Dependent Claim
30 words
A signal-conditioning circuit as claimed in claim 9, wherein the sensitivity and offset compensation means each include manually-adjustable gain adjustment means for enabling independent setting of the gain responses thereof.
Claim 12
Dependent Claim
35 words
A signal-conditioning circuit as claimed in claim 9, wherein, in use, the DC offset voltage and the gain applied to the transducer output signal both vary linearly with the excitation current drawn by the transducer.
Claim 13
Dependent Claim
60 words
A signal conditioning circuit as claimed in claim 8, wherein the gain control means of the sensitivity compensation means comprises a photo-sensitive resistor and a light emitting device optically coupled thereto, the sensitivity compensation means further including circuitry for deriving a sensitivity compensation voltage dependent upon the voltage drop across the sense-resistor and applying it to the light emitting device.
Claim 14
Dependent Claim
19 words
A signal-conditioning circuit as claimed in claim 1 including means for switching the polarity of the DC offset voltage.