Week -2

AIM-

1. Make a Simulink model of Doorbell using solenoid block with the following details :- In the above arrangement, when the switch is closed the electromagnet receives electrical power from the battery and pulls the metal arm to hit the bell producing sound.Create a situation where the switch is closed for 2 seconds and then released. Observe the physical movement of the plunger. 

Create a situation where the switch is closed for 2 seconds and then released. Observe the physical movement of the plunger. 

1. A doorbell using solenoid block.
2. Thermistor to use temperature sense of heater and turn off or turn on the fan.

SOLUTION -1

Theory- When you press a doorbell button, you complete an electrical circuit that allows household electricity to flow through the doorbell's internal electromagnet. The maganet field generated by the electromagnet  is then used to power a mechanisum that creates the doorbell sound.

• doorbell are low voltage devices.This means they require relatively  little energy to operate.An important part of a doorbell mechanism is the tranformer. The tranformer cover regular 120 volt household currnet to the lower voltage required by the doorbell.
• PS-simulink converter- 

   The default destination block units are meter-kilogram-second or MKS (SI). If you specify different units, commensurate with the expected default units of the destination block input, then the unit manager attaches these units to the input Simulink signal value and performs the necessary unit conversion when providing the signal to the destination block.

• Switch- rst of two data inputs. The block propagates either the first or second data input to the output. The block selects which input to pass based on the control input. Specify the condition for the control input to pass the first input using the Criteria for passing first input and Threshold parameters

• Battery-An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode
• solver configuration- 

  Each physical network represented by a connected Simscape™ block diagram requires solver settings information for simulation. The Solver Configuration block specifies the solver parameters that your model needs before you can begin simulation.

  Each topologically distinct Simscape block diagram requires exactly one Solver Configuration block to be connected to it.

• Ideal tranlational motion sensor-Connections R and C are mechanical translational conserving ports that connect the block to the nodes whose motion is being monitored. Connections V and P are physical signal output ports for velocity and position, respectively.The Ideal Translational Motion Sensor block represents a device that converts an across variable measured between two mechanical translational nodes into a control signal proportional to velocity or position. You can specify the initial position (offset) as a block parameter. The sensor is ideal since it does not account for inertia, friction, delays, energy consumption and so on
• pulse generator-The Pulse Generator can emit scalar vector or matrix signals of any real data type. To cause the block to emit a scalar signal  use scalars to specify the waveform parameters. To cause the block to emit a vector or matrix signal use vectors or matrices respectively to specify the waveform parameters. Each element of the waveform parameters affects the corresponding element of the output signal. For example, the first element of a vector amplitude parameter determines the amplitude of the first element of a vector output pulse. All the waveform parameters must have the same dimensions after scalar expansion. The data type of the output is the same as the data type of the Amplitude parameter.The block's Pulse type parameter allows you to specify whether the block's output is time-based or sample-based. If you select sample-based, the block computes its outputs at fixed intervals that you specify. If you select time-based Simulink computes the block's outputs only at times when the output actually changes. This can result in fewer computations being required to compute the block's output over the simulation time period.
• Mechanical translational referance-The Mechanical Translational Reference block represents a reference point, or frame, for all mechanical translational ports. All translational ports that are rigidly clamped to the frame (ground) must be connected to a Mechanical Translational Reference block
• Solenoid-The solenoid is a coil of wire, and the plunger is made of soft iron. The magnetic field is formed around the coil when an electric current passes through it and draws the plunger in. We can say that the solenoid is responsible for converting electrical energy into mechanical work.
• Scope-The Scope allows you to adjust the amount of time and the range of input values displayed. You can move and resize the Scope window and you can modify the Scope's parameter values during the simulation. When you start a simulation, Simulink does not open Scope windows, although it does write data to connected Scopes.

 SOLUTION-2

• AIM-   Thermistor to use temperature sense of heater and turn off or turn on the fan, As condition apply

• 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

  Signal Builder giving input vaues given as team condition
• Input are there as Quetion 
• 20°C time 0 to 10 seconds
• 27°C time 10 to 30 seconds
• 23°C time 30 to 50 seconds

1. Thearmistor - 

   Depending on materials used, thermistors are classified into two types:

   • With NTC thermistors, resistance decreases as temperature rises; usually due to an increase in conduction electrons bumped up by thermal agitation from the valence band. An NTC is commonly used as a temperature sensor, or in series with a circuit as an inrush current limiter.
   • With PTC thermistors, resistance increases as temperature rises; usually due to increased thermal lattice agitations particularly those of impurities and imperfections. PTC thermistors are commonly installed in series with a circuit, and used to protect against overcurrent conditions, as resettable fuses.

   Thermistors are generally produced using powdered metal oxides.With vastly improved formulas and techniques over the past 20 years, NTC thermistors can now achieve accuracies over wide temperature ranges such as ±0.1 °C or ±0.2 °C from 0 °C to 70 °C with excellent long-term stability. NTC thermistor elements come in many styles  such as axial-leaded glass-encapsulated (DO-35, DO-34 and DO-41 diodes), glass-coated chips, epoxy-coated with bare or insulated lead wire and surface-mount, as well as rods and discs. The typical operating temperature range of a thermistor is −55 °C to +150 °C, though some glass-body thermistors have a maximal operating temperature of +300 °C.

   Thermistors differ from (RTDs) in that the material used in a thermistor is generally a ceramic or polymer, while RTDs use pure metals. The temperature response is also different; RTDs are useful over larger temperature ranges, while thermistors typically achieve a greater precision within a limited temperature range, typically −90 °C to 130 °C.

2. Controlled tempurature source-

   The Ideal Temperature Source block represents an ideal source of thermal energy that is powerful enough to maintain specified temperature at its outlet regardless of the heat flow consumed by the system.

   Connections A and B are thermal conserving ports corresponding to the source inlet and outlet, respectively. Port S is a physical signal port, through which the control signal that drives the source is applied. You can use the entire variety of Simulink^® signal sources to generate the desired heat flow variation profile. The temperature differential across the source is directly proportional to the signal at the control port S.

   The block positive direction is from port A to port B. This means that the temperature differential is determined as T_B – T_A, where T_B and T_A are the temperatures at source ports.

   The block has the following ports:

   A=Thermal conserving port associated with the source inlet.

   B=Thermal conserving port associated with the source outlet.

   S=Physical signal input port, through which the control signal that drives the source is applied.

   Thermal reference- The Thermal Reference block represents a thermal reference point, that is, a point with an absolute zero temperature, with respect to which all the temperatures in the system are determined.

   Current sensor-The coreless open-loop sensors are based on Infineon’s precise and stable Hall technology. Thus the output signal is highly linear over temperature and lifetime. Due to lack of an iron core the sensor signal shows neither hysteresis nor does it suffer from saturation.
   The differential measurement with two Hall cells ensures high accuracy even in a noisy environment with cross-talk from adjacent current lines or magnetic stray fields. Designers can program the sensitivity of the sensor as well as the threshold levels of the two dedicated overcurrent signals and thus adapt them to individual requirements without any external components. The sensor also provides a signal in case of an over- or under-voltage condition for the supply voltage.

   DC-voltage source-The coreless open-loop sensors are based on Infineon’s precise and stable Hall technology. Thus the output signal is highly linear over temperature and lifetime. Due to lack of an iron core the sensor signal shows neither hysteresis nor does it suffer from saturation.
   The differential measurement with two Hall cells ensures high accuracy even in a noisy environment with cross-talk from adjacent current lines or magnetic stray fields. Designers can program the sensitivity of the sensor as well as the threshold levels of the two dedicated overcurrent signals and thus adapt them to individual requirements without any external components. The sensor also provides a signal in case of an over- or under-voltage condition for the supply voltage.

   voltage senson-

   The Voltage Sensor block represents an ideal voltage sensor, that is, a device that converts voltage measured between two points of an electrical circuit into a physical signal proportional to the voltage.

   Use the + and - ports to connect the sensor in parallel with the block (or several blocks) where you want to measure the voltage. Port V outputs the measurement result as a physical signal. Use a block to connect this port to Simulink blocks, such as Scope or Display.

   PS-CONVERTER- The Simulink-PS Converter block converts the input Simulink signal into a physical signal. Use this block to connect Simulink sources or other Simulink blocks to the inputs of a Simscape physical network.

   Ps switch-

   The Switch block models a switch controlled by an external physical signal. If the external physical signal PS is greater than the value specified in the parameter, then the switch is closed, otherwise the switch is open.

   Electrical switches add discontinuities to your model, and therefore your choice of the solver can influence the model behavior. For detailed information about the solver settings, see

   reference-Google,wikipedea,matlab books,www.electroschematics.com etc....