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172 Build Your Own Electric Vehiclechecklist from Alan—”You do have a driver’s license, don’t you?”—he slipped into thepassenger’s seat while I took over the wheel. After turning the key, one of the threebuttons on the left of the dash selects forward, neutral, or reverse. Once on the highway,the induction motor behaves like the smoothest automatic transmission imaginable,with one big difference. All the motor’s torque is instantly available at nearly any speed.After Alan counseled, “Don’t be afraid to step on it,” I did, and was abruptly pushedback into my seat while silently forming the word “Wow” on my lips. When I turned tolook at Alan, he was grinning from ear to ear. Next, Alan directed my attention to theregeneration lever on the right of the dash. All the way in one direction is fullregeneration. Take your foot off the accelerator pedal and the vehicle slows downimmediately, without even touching the brake. Push the lever all the way in the otherdirection and you have no regeneration. Take your foot off the accelerator pedal and thevehicle coasts and coasts.After I returned to earth, Alan gave me the walk-around tour, and talked about thebatteries (AC Propulsion’s Honda CRX uses 28 conventional 12-volt, deep-discharge,lead-acid batteries that produce 336 volts), controller, motor, charging philosophy, andtemporary instrumentation (to monitor performance).Back at their exhibit-hall booth, AC Propulsion employee Tiffany Mitchell showedoff the other benefit of the design (see Figure 7-7)—the incredibly small size of the motor!This 4-pole AC induction motor puts out 110 ft-lbs. of torque at anywhere from 0 to 5,000rpm, and an astonishing 120-hp maximum between 6,500 rpm and 10,000 rpm (maximumrpm is 12,000), yet it weighs only 100 lbs. Recall that Chapter 6’s recommended series DCmotor put out 70 hp maximum and weighed 143 lbs. Directly behind and above themotor on the booth table was the AC controller. It includes a 100-kVA PWM-style inverter;battery-charging circuitry; control logic; interfaces for control pedals, dash instruments,Fi g u r e 7-7 AC Propulsion’ s Tiffany Mitchell shows off an A C induction motor in front of an A Ccontroller/in verter of the 1990s.