How to make a device that can be plugged into a speaker and turned on with a flick of a switch

A couple of years ago, the inventor of the “Electrophoresist” app, a $2,500 gadget that uses an electrostatic force to convert audio into images, showed up at the Consumer Electronics Show in Las Vegas.The company, which has been making electrostatic sound devices for years, now has a product in the works.The Electrophoreser app uses an […]