I am doing project, I am trying to simulate an overvoltage/under voltage protection controller on LTSpice. How do I create overvoltage/unudervoltage on a source? For example a transient voltage spike? Please Help.
For a transient voltage spike you can click on your voltage source and under the advanced option choose the exponential output. Here you can provide the parameters for your spike such as the rise time and the fall time.
The absolute best method would be to construct a piecewise linear model (PWL).
In this, model you specify the voltage output at each time. Through linear interpolation the software will draw straight lines between these points and which will essentially construct your desired output.
A good reference: