Week -2

1) Doorbell

In the simscape model of the doorbell, the dc voltage source is connected to the solenoid through the switch which is operated by the signal generated by the pulse generator and is configurated according to the challenge question. In the solenoid, the spring stiffness and damping coefficient are tweaked to obtain the desired results. The solenoid is further attached to the mechanical translational sensor which senses the translation velocity and power of the attached system and the output of the power is plotted in the scope.

The model of the doorbell and pulse and power plots are attached below.

2)

In the simscape model of the second question, the signal generator is used to provide the varied temperature inputs according to the challenge to the variable temperature source which is attached to the temperature reference and thermistor input, it is also attached to the scope to verify the temperature output to the thermistor.

The thermistor is provided the current through the battery, the thermistor has a reference temperature of 298.15K on which the thermistor will close the circuit and let the current through according to the temperature characteristic constant B and it also varies the current according to the B and time delay which is reduced to 0.1 sec to obtain the desired output. The thermistor and battery are also attached to the resistor to create the voltage difference as all of them along with the current sensor are in the series connection. The resistor is parallelly connected to the voltage regulated switch which triggers at a specified voltage to switch on the fan at the desired temperature. This voltage-controlled switch is connected in series with a battery, resistor, and dc motor which powers the fan. And the mechanical part of the dc motor is connected to a mechanical rotational sensor that senses the rotation angle and rotational velocity of the fan and the scope is attached to the sensor to view the varying velocity of the fan.

The model of the above explanation along with the plots of output temperature from variable temperature source, the current passed through the thermistor and the rotational velocity of the fan are attached below.