Abstract: A method and apparatus for generating an AC voltage with user defined inductance and resistance values in series therewith is described. The output voltage of the AC source is sampled and a signal indicative of the total current being generated is derived. The signal is scaled to model a series resistance and scaled and differentiated to model a series inductance. The modelled series resistance and inductance are then combined with the output voltage. Different inductances and resistances can be modelled merely by changing the user's input to the microcontroller that controls the operation of the present invention.

Abstract: A power supply control circuit which enables the constant current and constant voltage feedback loops to be compensated independent of each other. In accordance with the invention, an inner feedback loop has been added which is local to the output stage so as to allow a constant voltage feedback loop to see a closed loop transfer function of the inner feedback loop that mimics an output for a constant voltage preferred output stage even though a constant current preferred output stage is used. As a result, load impedance variations that would have affected the loop gain of the constant voltage feedback loop affect the loop gain of the inner feedback loop only. The inner feedback loop is disposed such that it is automatically disabled by the constant current feedback loop when the power supply enters the constant current mode and hence allows the constant current and constant voltage modes to be decoupled from one another.