Sound Generators for EVs
Sound Generators for EVs
The good news about electric vehicles (EVs) is that they’re quiet. The bad news about EVs is that they’re quiet, so much so that when traveling at low speeds, like in neighborhoods or school zones, they’re silent enough to go undetected to the human ear, potentially catching pedestrians off guard. In fact, the U.S. Congress passed a bill in 2010 to make noise-generating devices mandatory on all silent-running vehicles. Delphi (delphi.com) has developed two eco-friendly sound generators, or “sounders,” for application in EVs that kick in when the vehicles are moving at 20 to 30 mph:
• Electronic Sounder System: A single-box system that’s three times lighter and 90% more energy-efficient than conventional multi-box systems. Provides a frequency range of 500Hz to 10 kHz.
• High-fidelity Sounder System: Uses a magnet-activated cone speaker to generate noise. Weighs 66% less than conventional speaker systems. Operates at a frequency of 150 Hz.
Both systems feature a 32-bit microprocessor with flash memory. They’re robustly designed to be embedded under the hood in all vehicle platforms. Additionally, they’re designed to allow vehicle manufacturers to customize the sound they generate.
While there’s no production date presently set for the High-fidelity Sounder, the Electronic Sounder System is scheduled to go into production in Europe in 2012.