Week -2
Challenge 2
Question1
The Primary circuit consists of the following blocks,
Battery, switch, solver config and a solenoid.
In order to create an input signal for the switch, a pulse generator was used with a time period of 4 seconds with pulse width of 50 percentage and a time delay of 2 seconds.
This signal is then passed onto the switch to simulate the switching action.
The primary circuit is also given an electrical reference.
The secondary circuit consists of the following blocks,
Solenoid, ideal translational motion sensor, PS converters and scopes for viewing the output.
The solenoid is modelled in such a way that the port moves from C to R. The motion of the solenoid is measured using an ideal translational motion sensor block which gives the position and velocity of the solenoid port vs time. The signal from this block is viewed in the scope.
The secondary circuit is also provided with mechanical translational references.
Analysis of output or result
It can be observed from the scope that when the switch is turned on at second 2 and 6, the signal is at an amplitude of 1 for 2 seconds which allows the position of the port in the solenoid to stay at around 2.4 for 2 seconds simulating the ringing of the bell.
In addition, to reduce disturbances in the output signal the solenoid properties were adjusted to have lower spring stiffness and higher damping coefficient.
Question 2
In order to create the input condition a signal builder block was used. It simulates the temperature change during the 50 second time span.
This signal is converted into a physical signal and given as input to a controlled temperature source block. This block is also given a thermal reference in the A port. The B port of the controlled temperature source is connected as input to the thermistor.
The electrical circuit consists of a thermistor, battery, voltmeter. Voltage sensor is connected in parallel to a resistor to measure the threshold voltage to be used in the switch block.
The fan mechanism is simulated using 2 constant blocks, 1 for ON and 0 for OFF. Finally, the output of the Fan is visualized in the scope.
Working.
The variation of temperature in simulated using a signal builder and the result observed using a scope. The created signal is converted into a physical signal using a PS converter and fed onto a controlled temperature source block. This block provides a heat source with required temperature difference to a thermistor. The thermistor is connected to an electrical circuit consisting of a battery, and a voltage sensor to measure the threshold voltage.
The threshold voltage was measured to be 0.011 V, this was done by connected a constant input of value 298K to the temperature source. The threshold voltage is set as a parameter for the switching action.
From the output scope it can be seen that the FAN operation/(output of 1) is between the time intervals of 10 and 30 seconds.