Control Systems

Question 1

3. With reference to a control system,
   John Willison IAMI Revision 41
   a) List four examples of a measured variable. (8)
   b) State the meaning of “two-step controller” and outline its basic action. (4) c) State the meaning of “proportional controller” and outline its basic actions. (4)

Answer 1

d) Voltage.
Frequency.
Temperature.
Pressure.
e) There are only two methods of operation, i.e. start and stop. It will start at a set point and stop at a set point.
f) There will be a master and slave control and the master control will monitor the input and the slave will monitor the output. The output signal is controlled against the input variable; the process is altered to achieve a constant output proportionally between full on and full off conditions