Week -2
AIM : To make a simulink model of a door bell using solenoid block
To use a thermistor to sence the temperature of a heater and turn on or turn off the fan
1 DOORBELL SIMULINK MODEL:
Simulink model explanation:
The pulse generator is used to create square wave pulse at regular intervals. The block waveforms parameters amplitude,pulse width, period and phase delay to determine the shape of the output forms.
The switch block used is controlled by external physical signal. if the external signal is greater than the thresold parameters then switch is closed, other wise switch is open.
The positive terminal of the switch is connected to the negetive terminal of the electrical referance.
The solenoid block is connected with switch and battery and we will get a complete electrical circuit. The port c is connected to the mechanical reference.
The ideal traslational sensor is connected with solenoid block R to observe the moment of the plunger.
Scope is connected to the ideal translational sensor to get the output.
PS-Simulink converter is used to convert the physical signal to the simulink signal.
Solver configuration each physical network represents by a connected simspace blocks requries setting information for simulink.
OUTPUT RESULTS
Time period is 2 sec the pulse generator to open and close the switch. When the switch is closed the soleniod blocks receives from the electrial power from the battery and plunger moves port Rto C to hit the bell and produce sound.
2. THERMISTOR
GIVEN INPUTS:
Temperature source: 20 deg.c from 0 to 10 seconds,27 deg.c from 10 to 30 seconds,23deg.c from 30 to 50 seconds.
Fan conditions: ON if the temperature is above 25 deg.c otherwise OFF
SIMULINK MODEL:
EXPLINATION:
Signal builder is addad to some input values as per the given conditions
At point 1 time= 0 seconds, Temperature= 293K
At point 2 time= 10 seconds, Temperature= 293K
At point 3 time= 10 seconds, Temperature= 300K
At point 4 time= 30 seconds, Temperature= 300K
At point 5 time= 30 seconds, Temperature= 296K
At point 6 time= 50 seconds, Temperature= 296K
Controlled temperature source represents an ideal source of thermal energy that can maintain a controlled temperature difference regardless of the heat flow. The temperature difference is by the physical signals port S.A positive temperaturs difference causes the temperature at port B to be greater than the temperature at port A.
Thermistor is a type resistor whose resistance is based on temperature.
A linear resistor is used in order to control the the amount of current from the battery.
The voltage sensor is used to convert the voltage measured between two poins into a physical signal.
voltage source which is represents dc or ac
Electrical referance block is given
Solver configuration: Each physical natwork is represented by a connected simspace block requries solver setting information for simulation.
OUTPUT :
For 0 to 10 sec the fan is OFF condition because temperature is 293k which is below the theshold value 298k
After 10 sec temperature goes to 300k then fan switch will ON condition as the temperature exceeds 298k. after 30 sec the fan will OFF as the temperature comes down to 296k which will be the theshold temperature of 298k.
From the above conditions,all the values are evaluated.