 # FIGURE 2.1 The purpose of linearization is to provide an output that varies linearly with some variable even if the sensor output does not. Curtis.

## Presentation on theme: "FIGURE 2.1 The purpose of linearization is to provide an output that varies linearly with some variable even if the sensor output does not. Curtis."— Presentation transcript:

FIGURE The purpose of linearization is to provide an output that varies linearly with some variable even if the sensor output does not. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

FIGURE The simple voltage divider can often be used to convert resistance variation into voltage variation. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

FIGURE 2.5 The basic dc Wheatstone bridge.

FIGURE When a galvanometer is used for a null detector, it is convenient to use the Thévenin equivalent circuit of the bridge. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

FIGURE 2.8 The current balance bridge.

FIGURE 2.9 Using the basic Wheatstone bridge for potential measurement.

FIGURE 2.10 A general ac bridge circuit.

FIGURE 2.11 The ac bridge circuit and components for Example 2.10.

FIGURE (a) Bridge off-null voltage is clearly nonlinear for large-scale changes in resistance. (b) However, for small ranges of resistance change, the off-null voltage is nearly linear. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

FIGURE 2.13 Circuit for the low-pass RC filter.

FIGURE 2.14 Response of the low-pass RC filter as a function of the frequency ratio.

FIGURE 2.15 Circuit for the high-pass RC filter.

FIGURE 2.16 Response of the high-pass RC filter as a function of frequency ratio.

FIGURE 2.17 Cascaded high-pass RC filter for Example 2.13.

FIGURE 2.18 Analysis of loading for a high-pass RC filter in Example 2.14.

FIGURE 2.19 The response of a band-pass filter shows that high and low frequencies are rejected.

FIGURE 2.20 A band-pass RC filter can be made from cascaded high-pass and low-pass RC filters.

FIGURE 2.21 Band-pass response for the filter in Example 2.15.

FIGURE Response of a band-reject, or notch, filter shows that a middle band of frequencies are rejected. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

FIGURE 2.23 One form of a band-reject RC filter is the twin-T.

FIGURE 2.24 The twin-T rejection notch is very sharp for one set of components.

FIGURE 2.25 The schematic symbol and response of an op amp.

FIGURE 2.25 (continued) The schematic symbol and response of an op amp.

FIGURE 2.26 The op amp inverting amplifier.

FIGURE Nonideal characteristics of an op amp include finite gain, finite impedance, and offsets. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

FIGURE 2.27 (continued) Nonideal characteristics of an op amp include finite gain, finite impedance, and offsets. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

FIGURE 2.28 Some op amps provide connections for an input offset compensation trimmer resistor.

FIGURE 2.29 Input offset can also be compensated using external connections and trimmer resistors.

FIGURE 2. 30 The op amp voltage follower
FIGURE The op amp voltage follower. This circuit has unity gain but very high input impedance. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

FIGURE 2.31 The op amp summing amplifier.

FIGURE 2.32 The op amp circuit for Example 2.18.

FIGURE 2.33 A noninverting amplifier.

FIGURE 2.34 The basic differential amplifier configuration.

FIGURE 2.35 An instrumentation amplifier includes voltage followers for input isolation.

FIGURE 2.36 Solution for Example 2.20.

FIGURE 2.37 This instrumentation amplifier allows the gain to be changed using a single resistor.

FIGURE 2.38 Bridge for Example 2.21.

FIGURE 2.39 A voltage-to-current converter using an op amp.

FIGURE 2. 40 A current-to-voltage converter using an op amp
FIGURE A current-to-voltage converter using an op amp. Care must be taken that the current output capability of the op amp is not exceeded. Curtis Johnson Process Control Instrumentation Technology, 8e] Copyright ©2006 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

FIGURE 2.41 An integrator circuit using an op amp.

FIGURE 2.42 This circuit takes the time derivative of the input voltage.

FIGURE 2.43 A nonlinear amplifier uses a nonlinear feedback element.

FIGURE 2.44 A diode in the feedback as a nonlinear element produces a logarithmic amplifier.

FIGURE 2.45 Model for measurement and signal-conditioning objectives.

FIGURE 2.46 One possible solution to Example 2.24.

FIGURE 2.47 One possible solution for Example 2.25.

FIGURE 2.48 ac bridge for Problem 2.14.

FIGURE 2.49 Circuit for supplementary problems.

FIGURE 2.50 System for Problem S2.4.

FIGURE 2.51 Nonlinear amplifier using diodes for Problems S2.6 and S2.7.