Q1. Describe, with the help of a proper diagram, how the piston of a hydraulic ram can be mechanically linked to the input servo valve to get a negative feedback servomechanism.  describe how a position demand is met.

Q2. Suppose that you are employed by a company which manufactures hydraulic servomechanisms.  You have been asked to suggest an electrical method of providing position feedback instead of the mechanical method used at present. The demand signal has been selected to be a d.c. voltage. Cost-effectiveness and reliability are necessary.

Examine the position sensor options and choose a cost-effective and reliable solution. Validate your selection.

Sketch a closed-loop block diagram of modified hydraulic servomechanism, recognizing the sensor, its signal conditioning and the form of error detector. You can suppose that the servo valve will be operated by a progressive solenoid which receives its operating current from the voltage-to-current converter.