Abstract: A duplex controller with a pair of redundant processor circuits connected by an update bus for use in a system which requires high reliability. Each of the redundant processor circuits is individually capable of performing the tasks of the duplex controller, so that the controller remains operable when one of the processor circuit members fails. The update bus is connected so that when the active circuit member executes a write command, the write command is also effected at the standby circuit. In this manner the memory state of the standby is dynamically maintained so that when control of the duplex controller is transferred from the active to the standby to the standby circuit, the standby circuit is instantaneously ready with up to date information to assume all processing responsibilities of the duplex controller without unnecessary delay.

Abstract: 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.