Week -2

AIM:

To make a simulink model of doorbell using solenoid cell and to make a simulink

Model of a thermistor to sense the temperature of heater and turn on/turn off the fan as per

The temperature conditions.

SOLENOID CELL:

A solenoid cell is a device comprised to a coil of wire, the housing and a moveable plunger (armature). When an electrical current is introduced, a magnetic field forms around the coil, which draws the plunger in more simply, a solenoid cell converts electrical energy into mechanical work.

DOORBELL USING SOLENOIDCELL:

Solenoid cell is electromagnet that converts the electrical energy in to mechanical energy. The current passing through the conducting wires a magnetic field is generated, around it which attracts the magnetic materials.This phenomina is used in bell,when the switch of the bell is pressed the current passes through the circuit exciting theelectromagnet and pulling the plunger towards the metal portion it produces ringing sound of solenoidcell.

SIMULINK MODEL:

The below image shows that pulse pattern as input, that cycle is 20 seconds. As we want the circuit is close only the interval of 2 sec a switch block is used. The switch block has threshold value 0.8 the threshold value of the pulse generator is 1 the switch will close only the threshold value is more than 0.8v then connected to solenoid block which connected toplunger arrangement initially when the plunger is away from c the value of x is 5mm and plunger is near c the value of x is 0mm.This can be seen from the output graph of plunger distance vs time.The position of plunger is obtained by using ideal translational motion sensor.

Signal input

FAN CONTROLLED BY THERMISTOR:

Thermistor is a sensor which is used to measure the temperature of the surrounding by comparing it with a known temperature and resistor values,the conditions are:

0-10seconds 20 degree Celsius

10-30seconds 27degree Celsius

30-50seconds 30degree Celsius

The input signal corresponding to the above parameters is given using signal builder block

SIMULINK MODEL:

The fan should be turned on when the temperature sensed is greatherthan 25 degree celsius.to fullfill this objective we use a voltmeter to find a voltage of circuit at different temperatures.it is found that,voltage at 25degree celsius is approximately 0.23v,that voltage signal is passes through a switch.

Output