Week -2
Aim: To make a doorbell sytem using solenoid block.
And to Use a thermistor to sense the temperature of heater and turn on or off the fan.
Doorbell System : A doorbell is a signalling device placed near a door to building entrance when visitor presses a button the bell rings inside the building alerting the occupant to the presence of the visitor .
Fig: doorbell system.
Simulink Model of a doorbell system .
In Simulink model of a doorbell system we use following blocks to form a doorbell system using simulink library
For Doorbell system following simulink block is used .
- pulse generator
- scope
- electrical reference
- Ideal translational motion sensor
- Mechanical translational reference
- battery
- Solenoid
- Switch
Pulse generator :
Pulse type determines the computational technique used.
Time-based is recommended for use with a variable step solver, while Sample-based is recommended for use with a fixed step solver or within a discrete portion of a model using a variable step solver.we connect the pulse generator to the scope and ps simulink converter for input values .
Scope : We use scope block to the graph of pulse generator .
Electrical reference : A model must contain at least one electrical reference port electrical ground .
Ideal Translational Motion Sensor :
This block measures velocity or displacement in a mechanical translational network. The sensor is ideal since it does not account for inertia, friction, delays, energy consumption, and so on.
The physical signal ports V and P report the velocity and position, respectively, of port R relative to port C. The measured velocity is positive when the velocity at port R is greater than the velocity at port C.
Mechanical translational reference : This block represents a mechanical translational reference point, that is, a frame or a ground. Use it to connect mechanical translational ports that are rigidly affixed to the frame (ground).
Battery:
This block models a battery. If you select Infinite for the Battery charge capacity parameter, the block models the battery as a series internal resistance and a constant voltage source. If you select Finite for the Battery charge capacity parameter, the block models the battery as a series .
Solenoid : The plunger Maximum stroke is implemented as a hard stop, the dynamics of which are set by the Contact stiffness and Contact damping parameters. The same parameters are used to model the contact dynamics when the plunger pulls fully in. The Spring constant parameter is used to implement a spring force that pulls the plunger out, and can be set to zero.
Switch:
The block represents a switch controlled by an external physical signal. If the external physical signal PS is greater than the threshold, then the switch is closed, otherwise the switch is open.
The closed resistance is defined by parameter R_closed, and the open conductance is defined by parameter G_open. Both parameters must be greater than zero.
Thermistor:
