bilateral converters are disclosed which translate direct current voltages at one level to direct current voltages at another level . the same converter can also be used to translate direct current voltages at the second level back to direct current voltages at the first level . the converter is bilateral in the sense of converting direct current energy in both directions from a higher to a lower voltage level and from the lower to the higher level . a switching signal interrupts the direct current at the first voltage level and a transformer is used to step up or step down the voltage level . the output voltage is rectified to provide direct current power at the second voltage level . the same action takes place in the opposite direction in response to nothing more than a change in the loading placed on the system .