Note also that Tesla defined the market as 0-60, not 0-100 or time for the quarter mile, both of which would favor a gas engine competitor.
Focusing on the power train resulted in a manageable project for a small team of engineers. The battery was the primary focus since you need a lot of stored electricity to move a 2,700-pound car at sports car speeds over an acceptable distance between charges.
Here, Tesla managed to use existing electronics IP in a novel way.
The battery is composed of 6,831 standard 18650 lithium-ion cells (somewhat larger than a standard AA-size battery) used in most laptop batteries. These batteries have to be closely matched and kept in a tight temperature range, which dictated the physical design of the battery pack with a liquid cooling system.
Other standard automotive IP "" radiator and fans "" were used to implement the battery cooling system. Along with controlling electronics, a reliable 53 KW/h battery could be constructed from all those cells.
Matching the battery with an AC induction motor enhanced by Tesla Motors, and power electronics to convert the battery's 370 volt DC output to variable frequency AC, yielded a power train that could achieve the necessary performance goals.
As with most innovative new projects, an unexpected difficulty caused a significant slip in the schedule. The more or less standard two-speed transmission initially chosen wouldn't handle the torque of the electric motor, typically failing in the initial prototypes after about 10,000 miles.
Designing a new one-speed transmission delayed introduction of the Tesla by nearly a year. By modifying the power electronics to get more power to the motor, designers managed to achieve the desired acceleration using a single gear, greatly simplifying the transmission.
As in most high-tech projects, a schedule slip due to one reason was used as an opportunity to improve other aspects of the car, and the result is a more refined vehicle.
The end result is the Tesla Roadster, a car with outstanding performance "" 0-60 in 3.9 seconds "" and good range "" 244 miles on a single charge, which can be done in as little as 3.5 hours. I recently heard someone ask another owner if the Tesla is as fast as advertised. His answer was the same as mine: "Yea, pretty much."
In some ways, the Tesla gives the impression of being an elaborate peripheral device. It is a car an electrical engineer can love.
Innovation and electronic design
The Tesla Roadster is a perfect example of an innovative product, but is there any relationship between it and electronic design? Tesla did not design any of their own semiconductors, so we can only look it as general inspiration for design innovation.
Tesla didn't go for incremental improvement, but its designers also did not try to reinvent the wheel. The project focused on a central part of the car, and let that drive the engineering effort. A significant amount of existing IP was reused in the Tesla design.
No amount of incremental improvement to an internal combustion engine would produce a zero-emission vehicle, so the designer made a technology leap where it was necessary.
In cars, as with electronic design, it has been observed by an unknown author: "You can't expect to meet the challenges of today with yesterday's tools and expect to be in business tomorrow."
The electronic design industry needs to remember examples like Tesla. When setting your sights on an ambitious goal, develop a well thought-out plan, embrace new technology with an acceptable level of maturity and put all your effort behind it. If you do, good things are bound to happen.
John Sanguinetti is chief technology officer at
Forte Design Systems> in San Jose, Calif.