6volt h bridge circuit
If the 6V source is regulated you can just add a diode in series with the base of the PNP transistors to achieve an additional drop of 0.7V (the arrows in the schematic are wrong). If not you´ll need a more complex circuit. Furthermore, you NEED to add limmiting resistors in series with ALL transistor´s bases (when you apply 0V to B you´re applying 6V to the junction of transistor 3).Can´t figure out how is it working. Also, a snubber circuit is welcome.