alt Hacker NewsI also associate ozone with some electric motors, I think because they have brushes that arc during operation. Older power tools I encountered in the 1980s often did this, and you could see the blue arc if you looked into the vents at the right angle.
Brushless motors are popular now, but if you get the cheaper cordless tools they'll still have brushed motors. I have some Black & Decker 20V ones that do it. They tend to have less torque but I don't need Milwaukee or Makita tools just for diy around the house.