Week -2

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

In the above arrangement, when the switch is closed the electromagnet receives electrical power from the battery and pulls the metal arm to hit the bell producing sound.

Create a situation where the switch is closed for 2 seconds and then released. Observe the physical movement of the plunger.

Following Blocks are used in Model:

Solenoid: Electrical characteristics and generated force of solenoid

Battery: To provide DC model.

Mechanical Translational Reference: Reference connection for mechanical translational ports

Ideal Translational Motion Sensor: Motion sensor in mechanical translational systems

Switch: Switch controlled by external physical signal

Pulse Generator: Generate square wave pulses at regular intervals

PS-Simulink Converter: Convert physical signal into Simulink output signal

Question 2- Use a thermistor to sense the temperature of a heater & turn on or turn off the fan as per the 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

Following Blocks are used in Model:

Signal Builder: Create and generate interchangeable groups of signals whose waveforms are piecewise linear

Simulink-PS Converter: Convert Simulink input signal into physical signal

Controlled Temperature Source: Variable source of thermal energy, characterized by temperature

Thermal Reference: Reference connection for thermal ports

Solver Configuration: Physical Networks environment and solver configuration

Thermistor: Negative temperature coefficient thermistor using B-parameter equation

DC Voltage Source: Constant voltage source

Resistor: Linear resistor in electrical systems

Voltage Sensor: Voltage sensor in electrical systems

Electrical Reference: Connection to electrical ground

Switch: Combine multiple signals into single signal

Constant: Generate constant value

Scope: Display signals generated during simulation

As per given conditions, the input signal (In kelvin) is generated in signal Builder block, which shown in above figure a(Input).

Table Based on simulation result:

Time	Temperature		Voltage sensor output	Switch output	Fan Condition
0 to 10	20 °C	293 K	0.0041	0	OFF
10 to 30	27 °C	300 K	0.0054	1	ON
30 to 50	23 °C	296 K	0.0046	0	OFF

As per input the voltage sensor which is connected across resistor is generate signal which is shown in Figure b ( Voltage sensor output after PS-Simulink Converter). Based on the figure b, Threshold limit set on 0.005 in switch block, It means during 0 to 10 seconds and 30 to 50 seconds the output of Voltage sensor is near to 0.0041 and 0.0046 respectively, meanwhile switch output is 0(Fan off). But, during 10 to 30second when temp. Above 25°C (above 298 K) switch output become 1(Fan on).