Week -2
Challenge 1
Aim
To make a simulink model of a door bell using solenoid block.
Project details
A solenoid is electromagnet.When the current is pass through the electromegent the coil magnetic field is generated in it,if the you place a metal core inside the coil the magnetic lines of flux is concentrated to the core which increases the induction of the coil as comapared the air coil.
- The postive terminal of the coil is connected to the spst switch and the negative terminal is connected to the negitve terminal of the battery.
- The postive terminal of the battery is connected to the spst switch.
- Spst is connected pulse genterator to give pulse for every 2 second when the spst is closed.we can observe the graph in the scope for every 2 seconds in the below image.
- we solver configuration and electrical reference is connected in the network.
- The r port of the solenoid is connected to the to translational motion sensor.It is used to detect the movemnt of ther plung .
- The c port is connected to the c port of the translational motin sensor which common referenece port is connect the mechanical reference to it.
- There are 2 more ports in the Translational motion sensor which the used to measure the velocity and position of the plung.
As we can see in the plotted graph above the change in velocity after 2 sec interval which intern represents the movement of the plung when the spst is closed.
We can obseve the change in postion of the after every 2 seconds.
Conculsion
In order to obatin the the doorbell simulation ,a solenoid is used to convert electrical energy into mechincal energy,in which the plung strikes the bell.
we have plotted some graph regarding the velocity and postion of the plung.
Challenge part 2
Aim :Use the thermister to sense the temperture of the heater and turn off or turn on the fan as per the condition given below
Temperature source condtion:20 degree c from 0 to 10 seconds,27 degree c from 10 to 30seconds,25 degree c from 30 to 50 seconds.
Fan conditions : Turn on the fan above 25 degree c or fan is off.
Similunk blocks used in the simulation model
Thermister: It is a sensor which is used to sense the temperature change in the system gives the output in the form of electrical signals.
controlled temperature source:This block represents the ideal energy source in a thermal metwork that maintain a controlled temperture regardless of heat flow rate
Signal builder:This block is used to give input to the thermister in kelvins at set time interval.
resistor : used to get the voltage across the thermistor.
Voltage sensor: used to sense the voltage across the resistor.
Switch: used to switch on and off condtions.
Controlled voltage source: used to control the voltage from the switch.
dc motor: represents the elctrical and torque characteristcs of dc motor.
Motion sensor:used to sense the motion in the dc motor.
The below model represents the simulation
working procedure of this model
The run time given to this model is 50 seconds.The signal builder send the signal to the controlled temperature source.Its checks for the temperature difference and send the signal to the thermister .The generated voltage is sensed by the voltage sensor through the resistor.The display displays the output and corresponding graphh is plotted as below.
The switch condition is such that it will operate only when U2 is greater the threshold.U2 is 0 and threshold is 2.otherwise it will not pass the voltage to the voltage controller.When the voltage is detected by the by the voltage controller and the dc motor starts to run.Rotational motion sensor is used to sence the movement of the dc motor.and the corresponding graph is obtained.
The above plot represents the velocity of the dc motor,As we can observe fan is in motion in betwwen 10 to 30 second which is on condition.
The above graph represents the angular displacement of the dc motor.The angular displacement is in between 10 to 30 second.
Results
The criterion of thermister model to measure the temperature is done using similunk model and the results are verified.