Week -2

Aim:

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.

A bell works with the principle of working of electromagnetism. When the armature moves towards the electromagnet, the hammer strikes the gong and the bell rings. As the armature moves towards the electromagnet, the contact with the adjustment screw breaks which breaks the closed circuit and stops the current.

A solenoid is a device comprised of 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 converts electrical energy into mechanical work.

Simulink model :

Input pulse settings :amplitude is adjusted to 4 ,time delay of 2sec,pulse width of 50% and period of 4sec

input signal

input signal provided by pulse generator block

now it has to be converted to the simulink physical signal hence SIMULINK PS is used component such as battery ,solenoid,electrical and mechanical refrencess are connected accordingly also solver configuration is attached

output

he can see the vibration due to the bell ring with the time time interval of 2 sec and the delay of 2sec.

Thermistor

A thermistor is a resistance thermometer, or a resistor whose resistance is dependent on temperature. The term is a combination of “thermal” and “resistor”. It is made of metallic oxides, pressed into a bead, disk, or cylindrical shape and then encapsulated with an impermeable material such as epoxy or glass.

Input to the block Signal builder

inputs are according to the conditions given.

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

we have to first modifies the setting of Simulink physical signal converter in the input side as we are using two heat source

then connect the componenets such as current sensor, controlled temperature source ,switch ,constant ,display block.Hence the fan will remain on from 10 to 30 sec