PS Subtract

Compute simple subtraction of two input physical signals

Libraries:
Simscape / Foundation Library / Physical Signals / Functions

Description

The PS Subtract block subtracts one physical signal input from another and outputs the difference:

$O = I_{1} - I_{2}$

where

I₁	Physical signal at the first input port (marked with the plus sign)
I₂	Physical signal at the second input port (marked with the minus sign)
O	Physical signal at the output port

Physical signals at the two input ports must have commensurate units. The unit at the output port is determined by unit propagation rules. For more information, see Physical Signal Unit Propagation.

Examples

Nonlinear Inductor

An implementation of a nonlinear inductor where the inductance depends on the current. For best numerical efficiency, the underlying behavior is defined in terms of a current-dependent flux. In order to differentiate the flux to get voltage, a magnetizing lag is included. Simulation results are relatively insensitive to this lag provided that it is at least an order of magnitude faster than the fastest frequency of interest. Parameters for the source and lag are defined in the MATLAB® workspace so that the expected voltage can be calculated analytically.

Open Model

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

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I1 — Input physical signal, untyped
physical signal

First input physical signal. In the block icon, this port is marked with a plus sign (+).

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.

I2 — Input physical signal, untyped
physical signal

Second input physical signal, to be subtracted from the first. In the block icon, this port is marked with a minus sign (-).

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.

Output

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O — Output physical signal, untyped
physical signal

Output physical signal.

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.

Extended Capabilities

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

Version History

Introduced in R2007a

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R2019a: Unit Propagation

Prior to R2019a, this block did not propagate physical units.

If your model contains legacy blocks without unit propagation, use the Upgrade Advisor to upgrade your blocks to the latest version. For more information, see Upgrading Models with Legacy Physical Signal Blocks.

PS Subtract

Description