Problems require extending the concepts of this chapter to

new situations.

The following systems may be described by a block

diagram showing the cause-effect relationship and

the feedback (if present). Each block should de-

scribe its function. Use Figure 1.3 as a model where

appropriate.

P1.1 Many luxury automobiles have thermostatically

controlled air-conditioning systems for the comfort

Human

operator

Fluid

flow

Valve

Meter

Process

FIGURE P1.2 Fluid-flow control.

Output

of the passengers. Sketch a block diagram of an

air-conditioning system where the driver sets the

desired interior temperature. Identify the function

of each element of the thermostatically controlled

cooling system.

P1.2 Control systems can use a human operator as

part of a closed-loop control system. Sketch the

block diagram of the valve control system shown in

Figure P1.2.

Control rod

FIGURE P1.4

Problems 41

Ionization chamber

Nuclear reactor control.