Week -2

Objective

1. Make a Simulink model of Doorbell using solenoid block.
2. Use a thermistor to sense the temperature of a heater & turn on or turn off the fan if the temperature above 25 °C, OFF otherwise.

Doorbell

Model explanation

First of all there will not be any bell tool in the matlab librery so that we just sense the translational motion created at "A" in the lever using a motion sensor.

Pulse generator is used to create a square wave with amplitude = 1, period =4, phase width = 50, phase delay = 0.

ps-s converter and s-ps converter is used to convert signals from simulink to physical and vice-verca.

Graph obtained from this study

Here we can see that we get a vibrational motion in the graph and this vibrational motion will produce a belling action

Heater

Here provided temperature and time relation, we use that data to create our input. using this we run the heater model from that we know that this above 0.012v we want to start the fan, so we give the switch threshold as 0.012 and if greater than that value switch shows 1 otherwise 0.

Graph

The first graph shows the signal builder input.

second graph is the voltage variation across resistor with respect to time.

This last graph shows the on and off condition of fan

• when it is 0 fan is in the off condition
• when it is 1 fan is in the on condition