Patent attributes
An inverter and battery charger system that uses no power magnetic components to convert DC power supply from a plurality of batteries to AC power and achieves very high efficiency and small size. The inverter takes advantage of the different voltages in a series string of batteries to create small voltage steps to approximate a sinewave or other waveforms. By changing the timing where the voltage steps are selected, different frequencies can be obtained. The low frequency operation of the inverter produces little radio frequency interference. The battery charger applies charging current to the various nodes in the series string of battery cells to charge each one as needed to accommodate the differing levels of discharge used to make a sinewave or other waveform.