ExpSine

```block ExpSine "Generate exponentially damped sine signal"
import Modelica.Constants.pi;

parameter Real amplitude = 1 "Amplitude of sine wave"
annotation (Dialog(groupImage = "modelica://Modelica/Resources/Images/Blocks/Sources/ExpSine.png"));
parameter SIunits.Frequency freqHz(start = 2) "Frequency of sine wave";
parameter SIunits.Angle phase = 0 "Phase of sine wave";
parameter SIunits.Damping damping(start = 1) "Damping coefficient of sine wave";

extends Interfaces.SignalSource;
equation
y = offset + (if time < startTime then 0 else amplitude * Modelica.Math.exp(-(time - startTime) * damping) * Modelica.Math.sin(2 * pi * freqHz * (time - startTime) + phase));

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Documentation(info = "<html>\n<p>\nThe Real output y is a sine signal with exponentially changing amplitude:\n</p>\n\n<p>\n<img src=\"modelica://Modelica/Resources/Images/Blocks/Sources/ExpSine.png\"\n     alt=\"ExpSine.png\">\n</p>\n</html>"));
end ExpSine;

```