Issue link: https://iconnect007.uberflip.com/i/1441485
JANUARY 2022 I DESIGN007 MAGAZINE 53 is installment of Target Condition is not intended to teach design for high voltage. I wrote it to implore our readers to learn about the risks and precautions which must be taken in the design and handling of high voltage electronics from the in-depth subject matter provided by the knowledgeable authors con- tributing to this issue. My message is one of awareness, to watch out for our fellow stake- holders and to inspire a healthy regard for any potential safety risks when utilizing high volt- age and high current. e target condition for the design of high voltage PCB layouts may be summarized as: "Mitigating potential to cause injury or harm." Let us read. Let us learn. And let us incorpo- rate knowledge about electrical safety for the benefit of our project stakeholders. A Low-Voltage Childhood As a kid, I went on to experience electric- ity in the ways kids do. As a Cub Scout, I made a lemon battery using galvanized nails, pennies, and some copper wire to power a flashlight bulb. I connected a 1.5V dry cell battery to the glow plug of my Cox .049 air- plane motor and understood how it served to ignite the fuel in the motor to get it to run. I survived a schoolyard challenge to touch both terminals of a Ray-O-Vac 9V battery to my tongue. I connected transformer termi- nal wires to my electric train set and enjoyed watching my friend's older brothers work on their electric slot cars they would race with incredible acceleration and speed at the local hobby tracks. I had a mostly "low-voltage" childhood expe- rience and I thankfully stopped short of elec- trocuting my young self through experimenta- tion with wall sockets and screwdrivers as did the kid over on the next block. Fiy years later (except for connecting jumper cables), I've mostly lost my fear of sparks and have been working in the low voltage realm designing printed circuit boards with some occasional high voltage requirements thrown in. A Shocking EV Car Experience Last May, I began driving a 75-mile round trip to work for a new employer. With the price of gas skyrocketing, I began to seriously consider getting into the electric vehicle mar- ket, so I started shopping. e first challenge was availability. It seemed there were no EVs available in the inland Pacific Northwest. But no sooner did I find a dealer with a new electric vehicle than I was informed that it was being recalled due to the failure of its high-voltage power system. Evidently some of these EV owners had their garages burned down by that particular model. ere go those pesky safety issues again. I'd read many positive EV reviews and evaluations. Except for that particular EV, it appears that the EV market has done very well in improve- ments, making the electric cars mechani- cally safe, thanks in part to all of the visibility brought about by Nader and the NHTSA. But now our next-generation electric vehi- cles are utilizing technology which has the potential to stretch safety concerns into unfa- miliar areas. In the high-voltage electric auto- Figure 2: EV HV charging station.