
The hysteresis effect associated with the thermostat, Equation 5.64, is illustrated graphically in Figure
2.38. This type of nonlinear behavior is readily simulated using a ‘‘Relay ’’ block from the Simulink
‘‘Discontinuities’’ sublibrary. A description of the ‘‘Relay’’ block can be found in the online
Simulink Reference, which contains detailed documentation for each block (see Figure 5.54).
A Simulink diagram for simulating building temperature with conditions as described in
Example 2.11 is shown in Figure 5.55. The ‘‘Relay’’ block parameter box is also shown.
The furnace output and building temperature are shown in Figure 5.56. The building