Week -2

1. Make a Simulink model of Doorbell using solenoid block with the following details:

Design a doorbell using solenoid block in simulink

Figure 1

Figure 1 shows the simulink model for designing doorbell

Pulse generator is used to operate the switch with delay of 2 seconds

Figure 2

Figure 2 shoes the moment of solenoid based on pulse generator

2. Use a thermistor to sense the temperature of a heater & turn on or turn off the fan as per below conditions:

Temperature source: 20 °C from 0 to 10 seconds, 27 °C from 10 to 30 seconds, 23 °C from 30 to 50 seconds

Fan conditions: ON if the temperature above 25 °C, OFF otherwise

Figure 3

Figure 3 shows the voltage drop across resistor at 25 C or 298 K is 0.01189 volts

Therefore switch to fan block value = 0.01189

if voltage value less than 0.01189 ----> switch position is off

voltage value greater than 0.01189 ----> switch position is on

Figure 4

Figure 4 shows using a thermistor to sense the temperature of a heater with different temperature values

In the above simulink model signal builder is used to vary the input temperature level to temperature source.

from 0 to 10 seconds -> temperature = 293K = 20 C

from 10 to 30 seconds -> tempreature = 300K = 27 C

from 30 to 50 seconds -> temperature = 296K = 23 C

Figure 5

Figure 5 shows the result of operating of switch to fan based on temperature value

in the switch position graph

• Time period from 0 to 10 sec and 30 to 50 sec ---> switch position off , as temperature less than 25 C or 298 K (voltage drop across voltage equal to 0.01189 volts).
• Time period from 10 to 30 sec ---> switch position on, as temperature greater than 25 C or 298 K (voltage drop across voltage equal to 0.01189 volts).