IIRC, Panasonic owns the patent on inverters, but they definitely make a microwave with a simple knob interface, because I have one (http://www.panasonic.com/au

IIRC, Panasonic owns the patent on inverters, but they definitely make a microwave with a simple knob interface, because I have one (http://www.panasonic.com/au/consumer/household/microwave-ovens/microwave-only/nn-sd351m.html http://www.panasonic.com/au/consumer/household/microwave-ove...)