Soderberg Manufacturing has developed its first external power supply. Although Soderberg has been integrating power systems and drivers into units for many years, this accomplishment came with an assortment of challenges and lessons that have and will continue to help to improve the quality of our electronics systems.
Power supplies generate Electromagnetic Interference (EMI) as a course of their normal function and EMI will cause innumerable problems on an aircraft; a power supply on an aircraft must generate EMI below required thresholds. The difficulty primarily lies in eliminating the electromagnetic noise without removing or reducing the power transmission or electrical signals the power supply is designed to generate or receive. Soderberg solved these problems to produce a unit that successfully passed all requirements of RTCA/DO-160.
The function of this particular power supply is unique compared to other power supplies: it provides thirteen discrete flash patterns in two different modes of operation for a total of twenty six individual power requirements. Each of these power requirements apply a different strain on the EMI filtering meaning that the EMI suppression used needs to be passively viable for twenty-six power loads.
In addition, the environment in which the power supply operates was a challenge in itself. Located within feet of an engine and suspended unsupported on mounting tabs this unit is subject to severe vibration as well as thermal variance provided by proximity to the engine itself. Combined with the harsh atmosphere created by the engine this power supply is subjected to a battery of conditions that could lead to unit failure. Every condition was accounted within the design and addressed to maintain functionality regardless of the environment.
Soderberg achieved a herculean task: creating a rugged, electrically clean power supply that can withstand some of the harshest environments on an aircraft.