Piecewise Linear Voltage Source

Time-dependent voltage source using lookup table

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Libraries:
Simscape / Electrical / Sources
Simscape / Electrical / Additional Components / SPICE Sources

Description

The Piecewise Linear Voltage Source block represents a voltage source that you specify in lookup table form using a vector of time values and a vector of the corresponding voltage values. You must specify at least two time-current value pairs. The block generates a time-dependent voltage based on these time-voltage values using the selected interpolation and extrapolation methods. You have a choice of two interpolation methods and extrapolation methods. The output voltage is independent of the current through the source.

Examples

Linear LED Driver

A LED driver based on a linear current regulator. The scope shows the light and current output and the supply voltage. The output comes into regulation for a supply voltage greater than about 12V.

• Open Model

Ports

Conserving

+ — Positive voltage

electrical

Electrical conserving port associated with the piecewise linear voltage source positive voltage

- — Negative voltage

electrical

Electrical conserving port associated with the piecewise linear voltage source negative voltage

Parameters

Time specification — Vector of time values

[0, 1, 2, 3, 4] s (default)

Vector of time values as a tabulated 1-by-n array. The time values vector must be strictly monotonically increasing.

Current at specified time — Vector of current values

[0, 0, 0, 0, 0] V (default)

Vector of voltage values as a tabulated 1-by-n array. The voltage values vector must be the same size as the time values vector.

Interpolation method — Interpolation method

Linear (default) | Smooth

Select the method that the block uses to determine the output current values at intermediate time points that are not specified in the preceding vectors:

• Linear — Prioritize performance by using a linear function.

• Smooth — Prioritize accuracy by producing a continuous curve with continuous first-order derivatives.

Extrapolation method — Extrapolation method

Nearest (default) | Linear

Select the method that the block uses to determine the output current values at time points that are outside the time range specified in the preceding vectors:

• Nearest — Select this option to use the nearest input value for extrapolation.

• Linear — Select this option to use a linear function.

References

[1] D. Kahaner, C. Moler, and S. Nash. Numerical Methods and Software. Prentice Hall, 1988.

[2] W.H. Press, B.P. Flannery, S.A. Teulkolsky, and W.T. Wetterling. Numerical Recipes in C: The Art of Scientific Computing. Cambridge University Press, 1992.

Extended Capabilities

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

Version History

Introduced in R2008a