Week -2

Q1)Make a simulink model of doorbell using solenoid block with the given details.

Ans.

AIM: To make a simulink model of a doorbell using solenoid block.

Doorbell using solenoid:

The solenoid is an electromagnet. On passing current through the coil, a magnetic field is produced that attracts the plunger (magnetic material), towards the metal portion of the bell, giving a ringing sound.

MODEL:

BLOCKS AND PARAMETERS:

Battery, Solenoid, Switch, Scope, Ideal translational motion sensor, Solver, PS-simulink converter, Simulink-PS converter AND a Pulse Generator block as an input.

The pulse is such that the switch is ON every 2 seconds.

INPUT SIGNAL:

Above pattern shows the pulse pattern in the given input.

We want the circuit to be close for an interval of 2 seconds, a switch block is used.

The amplitude of the pulse generator is 1 and threshold of the switch is 0.8.

OUTPUT: Initially the plunger is away from the C, at a distance of 5 mm, and when the plunger is near C, the value becomes 0 mm.This can be seen in the output graph of the plunger distance vs time. The position of the plunger is given by Ideal Translational Motion Sensor.

Q2)Use a thermistor to sense the temperature of a heater and turn off or on the fan as per given conditions.

Ans.

Given inputs:

Temperature source 293k from 0 to 10 seconds, 300k from 10 to 30 seconds and 296k from 30-50 seconds.

Fan conditions: On if the temperature goes below 298k.

MODEL:

BLOCKS:

-Signal Builder Block is used to input the values as per given conditions.

Scope, Controlled Temperature Source, Thermal Reference, Solver Configuration Box, Thermistor, Battery, Voltmeter, Linear Resistor, Electrical Reference, Switch, Voltage Source.

OUTPUT:

For 0 to 10 s fan is OFF, because temperature is 293k which is below 298k. After 10s to 30s temperature goes then the switch will be ON because the temperature exceeds 298k.

After 30s fan will be turned OFF, because the temperature comes down to 296k which is below the threshold temperature of 298k.

From the above conditions, all the values are evaluated.