Switch

Switch controlled by external physical signal

• 

Libraries:
Simscape / Foundation Library / Electrical / Electrical Elements

Description

The Switch block models a switch controlled by an external physical signal. If the external physical signal at port PS is greater than the value specified in the Threshold 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 Making Optimal Solver Choices for Physical Simulation.

Variables

To set the priority and initial target values for the block variables prior to simulation, use the Initial Targets section in the block dialog box or Property Inspector. For more information, see Set Priority and Initial Target for Block Variables.

Nominal values provide a way to specify the expected magnitude of a variable in a model. Using system scaling based on nominal values increases the simulation robustness. Nominal values can come from different sources, one of which is the Nominal Values section in the block dialog box or Property Inspector. For more information, see Modify Nominal Values for a Block Variable.

Examples

Solenoid

A solenoid with a spring return. The solenoid is modeled as an inductance whose value L depends on the plunger position x. The back emf for a time-varying inductance is given by:

• Open Model

Ports

Input

PS — Control signal, unitless

physical signal

Input physical signal that controls whether the switch is open or closed.

Conserving

p — Electric terminal

electrical

Electrical conserving port associated with one of the switch terminals. The block has no intrinsic directionality.

The port name is not visible in the block icon, but you can see this name in the underlying source file by clicking the Source code link in the Description tab of the block dialog box.

n — Electric terminal

electrical

Electrical conserving port associated with the other switch terminal.

The port name is not visible in the block icon, but you can see this name in the underlying source file by clicking the Source code link in the Description tab of the block dialog box.

Parameters

Closed resistance R_closed — Resistance of closed switch

0.01 Ohm (default) | positive scalar

The resistance of the switch when it is closed. The parameter value must be greater than zero.

Open conductance G_open — Conductance of open switch

1e-8 1/Ohm (default) | positive scalar

The conductance of the switch when it is open. The parameter value must be greater than zero.

Threshold — Threshold value for opening and closing switch

0.5 (default) | unitless scalar

The threshold value for opening and closing the switch. If the external physical signal at port PS is greater than this value, then the switch is closed, otherwise the switch is open.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2007a