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52 DESIGN007 MAGAZINE I JANUARY 2022 today as DFS—design for safety. He inculpated designers for not considering the effects of a car's interior on the human body during a crash, which was morbidly referred to as "the second collision." Nader's book is significant because he stood up to criticize "Big Auto" for cost-cutting on design safety. He used compelling data to make consumers tangibly aware of how they were being blamed by Detroit for the injury and harm caused by vehicular accidents. In effect, Nader identified the automotive consumer as a project stakeholder. He included automotive passengers and even crosswalk pedestrians as stakeholders for which consideration for avoid- ing the potential to cause injury or harm must be incorporated into every automobile design. What Has Changed in 50 Years? e safety issues described in Nader's book were mechanical by nature. I've searched for anything written about electrical safety con- cerns, but I've found no safety issues regarding high voltage electricity. Systems were low volt- age based on 6V or 12V systems. Cars didn't even use electricity until around the 1920s when electric starter motors were added to crank the motor over automatically to start the car. e earliest automotive electrical safety scare I can remember occurred when I saw sparks fly off the jumper cables when help- ing my dad jump start our old 1964 Volkswa- gen Karmann Ghia. I still cringe in fear while attaching jumper cables to this day. Over five decades later, many of the mechani- cal safety issues of the past have been addressed through the work of the National Highway Traf- fic Safety Administration (NHTSA). However, as we continue into the dawn of the advanced electric vehicle (EV) era, there continues to be new safety challenges to understand and to monitor as we experience the exponential growth in the development and utilization of high voltage systems into the cars we will drive. Defining High Voltage Many countries use different voltage and fre- quency standards for power distribution net- works. e U.S. uses 120V/60Hz while much of Europe and South Africa use a 230V/50Hz standard. Jamaica uses 100V/50Hz or 60Hz standard. Safety must be considered when bringing a high voltage potential onto a printed circuit design and breaking it down to lower operating voltages. But what potential is con- sidered high voltage in the first place? ere are many variables to consider when deter- mining what is high voltage. e minimum voltage experienced by a static (electrostatic discharge) shock is 3,000V but this is harmless due to its very low current. Some commissions define high voltage as >1,000V AC RMS and 1,500V for DC voltage. As designers of printed circuit-based elec- tronics know, there are design guidelines for voltage ranges and testing which must be included in design and manufacturing work- flows in order for a circuit board assembly to be certified as safe for intended applica- tions, including electric vehicles. IPC-2221 and IEC/UL 60950 are go-to specifications for those regarding creepage and clearance requirements for conductors to eliminate the occurrence of electrical arcing, which can be a potential cause of fire or electrical shock. Figure 1: A high-voltage warning.