Which sentence explains how a desired position for a controlled device is entered in a servomechanism?
a. how servomechanisms work servomechanisms have a command device, a controlled device, an error detector, an error-signal amplifier, and a mechanism to make error corrections: such as a servo motor.
b. let’s consider a task where the position of the controlled device is to be regulated. the controlled device is set up to generate a feedback signal (such as a voltage) that always gives its current position.
c. this signal is sent to the error detector. the command device is given data about a desired position for the controlled device, usually from outside the system.
d. this data is sent to the error detector by the command device in the form of a command signal (such as a voltage). the error detector compares the command signal (the desired position of the controlled device) with the feedback signal (current position of the controlled device).
e. the error detector notes any difference in these two signals and sends an error-correction signal to the amplifier. the amplifier produces a response (such as an amplified voltage) to drive the servo motor.
f. the servo motor moves the controlled device to the desired position.