Voltage Sag Generator

I was making a circuit to generate voltage sag signal as shown in the image in the link below: http://img830.imageshack.us/img830/5792/matlab.jpg

As you can see in the oscilloscope, there are two signals instead of one signal generated when I was trying to combine one sine wave signal with one step input. It is a product of a sine wave and a step input so supposed the answer should be only one signal. The mdl file can be downloaded here. Please advised. Much appreciated.

http://www.mediafire.com/?tvqsc94a23ac195

Answer 1

[Paulo Silva]

It's the step block that's generation the extra signal, I'm trying to find a fix for it, please wait

A way to fix it is to put a demux block in the output of the Product block and a Add block to add the demux outputs together, hope this helps.

[Kai Hao Then]

Thanks Paulo Silva. That helps. =)

[Amrutha S]

can we connect this with an HVDC inverter?two waveforms are there,pink and yellow,pink stands for what? and i think yellow stans for sag voltage