Issue link: https://iconnect007.uberflip.com/i/1441485
JANUARY 2022 I DESIGN007 MAGAZINE 41 had gotten a little too real for my imagination at that point, and I didn't want to take a chance on blowing up the city. ere were plenty of other interesting things about that trip such as exploring the aircra, playing with the radio equipment, training the guns around to get my sights on imaginary enemy aircra, and enjoying the trip as the pilots flew us across the countryside. Oh, and just for excitement, about halfway through the trip, the pilots announced that the plane had suffered a problem in the electrical system. ey didn't give us much in the way of details, but I did hear the phrase "a battery exploded," which resulted in the electrical system being knocked out on the le side of the plane. ankfully this didn't affect how the plane was flying, as an older plane like this didn't rely as much on electrical systems for flight as a mod- ern plane would. However, there was one big problem that was unavoidable: the pilot was unable to lower the le side main landing gear wheel and the tail wheel from the cockpit. As you can guess, without all of the landing gear down and locked, our landing was undoubt- edly going to end up in a crash. Understanding Higher Voltage Ever since that flight I've oen wondered about that electrical problem, and the mental image of a battery exploding somewhere in the internal workings of the B-17 is a very intriguing one to say the least. Did the battery suffer an internal short and failure, or did a mechani- cal anomaly cause something to get crossed up resulting in a more excit- ing short with sparks and smoke? Maybe the incident was due to an over-voltage problem somewhere, or just maybe the battery actually did explode? Whatever was the root cause of the problem, it is obvious that our plane experienced a seri- ous electrical power failure that was unplanned and a surprise for every- one on board. With that flight serving as an example of the consequences of an electrical failure, it has motivated me to understand more about the different requirements of power and higher voltages in my own small world of cir- cuit board design. Most PCB designers are aware of the unique power requirements for the garden-variety digital design. Power supply component placement must be kept tight to keep the trace routing as short as possible for lower induc- A view out the right side in the nose of the plane of the Wright Cyclones keeping us in the air. Cranking down the left main landing gear.