| 摘要 |
A signal-conditioning circuit for use in conjunction with transducers measuring simultaneously steady state and fluctuating parameters, e.g. pressure. The circuit comprises low-pass filtering means, preferably comprising an active filter, for removing the AC component of the transducer output signal representing the fluctuating component of the measured parameter, to produce a DC output signal representing the steady state component of the measured parameter; and subtracting means for subtracting the DC component from the transducer output signal to produce an AC output signal representing the fluctuating component of the measured parameter. The circuit is thus capable of producing simultaneous outputs representing separately the steady state, fluctuating, and combined components of the transducer output signal, with the introduction of little or no phase error. The invention also extends to a signal-conditioning circuit for use in conjunction with a transducer of the resistance bridge (strain gauge) type, including means responsive to variations in the temperature of the transducer, conveniently sensed by a sense resister arranged to detect variations in the excitation current drawn by the transducer, to vary the magnitude of a DC offset voltage, and the gain applied to the transducer output signal, whereby to compensate for temperature variations in the zero offset and sensitivity respectively of the transducer. |
