Practice Problems

Practice Problems#

Problem 1.#

  1. An inertial navigation system’s (INS) accelerometers put out \(-70\ \text{mV}\) when \(-5g\) is detected and \(20\ \text{mV}\) when \(5g\) is detected. An aircraft’s navigation system reads voltages between \(-7\ \text{V}\) and \(2\ \text{V}\) when the detected signal is between \(-5g\) and \(5g\). Design a signal conditioning circuit to adjust the INS to the nav system.

Problem 2.#

  1. An elevator for a UAS requires \(1\ \text{V}\) to move the elevator fully down and \(-9\ \text{V}\) to move the elevator fully up. The pilot’s control column (joystick) produces \(-1\ \text{mV}\) when fully down and \(4\ \text{mV}\) when fully up. Design the interface between the control unit and the actuator.

Problem 3.#

  1. For each of the following devices, determine whether it is an input transducer, an output transducer, both, or neither.

    a. Computer mouse

    b. Electric motor

    c. Stereo speakers

    d. Op amp

    e. Light bulb

    f. Electronic thermometer

    g. Transformer

    h. iPhone touch screen

    i. Control stick of a fly-by-wire aircraft

    j. Aircraft HUD (Head Up Display)

Problem 4.#

  1. Why don’t we use transformers to amplify information signals?

Problem 5.#

  1. A device that is used to add two or more signals is a

    a. Input transducer

    b. Output transducer

    c. Summer

    d. Instrumentation System

Problem 6.#

  1. A microphone converts an incoming voice signal to a range of \(\pm 2.5\ \text{mV}\). Design an instrumentation system to amplify this signal to drive a speaker which requires \(\pm 4\ \text{V}\).

Problem 7.#

  1. Using the instrumentation system you designed in Problem 7 above, what would the output voltage be if the signal from the microphone was \(1\ \text{mV}\)?

Problem 8.#

  1. The rudder control unit for a fly-by-wire aircraft produces a \(-2.5\ \text{mV}\) signal when fully left is desired and \(2.5\ \text{mV}\) for fully right. The rudder actuator requires \(-5\ \text{V}\) for fully left and \(+10\ \text{V}\) for fully right. Design the instrumentation system to allow the rudder system to work correctly.

Problem 9.#

  1. Design the instrumentation system between the flight control computer and the aileron actuators for an experimental UAS. The flight control computer generates a \(4\ \text{mV}\) signal when the ailerons need to be deflected \(15^\circ\) and a \(-16\ \text{mV}\) signal when \(-20^\circ\) deflection is needed. The aileron actuators require \(15\ \text{V}\) to deflect the control surface \(15^\circ\) and \(-10\ \text{V}\) to deflect the control surface \(-20^\circ\).

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