A voltage controller capable of generating a staircase voltage is made up of a plurality of energy storage devices series connected with respective solid state switch devices. The solid state switch devices can be turned on or off to connect different combinations of the batteries in series with the output of the controller, the voltage output being proportional to the number of batteries connected in series in any particular combination. By cycling between different switch combinations, and reversing the polarity of the output once every cycle, an approximated sine wave output can be obtained. By providing a voltage input, the device can also function as a voltage converter or transformer-like device. Individual steps can be pulse width modulated simply by controlling the switch combinations, and by adding a linear switch device at the input, analog modulation of the step voltages can be obtained.