Electric Cars, Past and Present Essay -- Electric Vehicles Green Envir

One of the main components of an electric vehicle (EV) is the controller. The controller takes power from the batteries and delivers it to the motor. To do this the accelerator pedal is hooked up to a pair of potentiometers, which provide the signal which tells the controller how much power it needs to deliver. For safety there are two potentiometers, the controller reads both potentiometers to make sure that their signal are the same, if the signals are not equal then the controller will not operate. For a car with a 300V battery the controller takes that DC voltage from the battery and converts it into a maximum of 240 volts AC to sent to the motor. This is done by using large transistors to quickly turn the batteries voltage on and off creating a sine waves. There are two types of controllers, DC (direct current) and AC (alternating current). A DC controller, in all simplicity, is basically just a big on/off switch that is wired into the accelerator pedal. When the pedal is pushed in, the switch is on, and when the pedal is not pushed in the switch is off. So while you are driving you need to push and release the accelerator to pulse the motor on and off to maintain a constant speed. While this would work who can imagine actually driving like that so the controller does this pulsing for you. The controller reads the setting of the accelerator from the potentiometers and regulates the power as needed. For example, if the accelerator is pushed 50% of the way down, the controller would rapidly switch the power to the motor on and off so that it is on half of the time and off half of the time. Likewise, if the pedal is pushed 75% down the controller pulses the power so that if is on 75% of the time and off 25% of the time. .. ...e jeeps had a top speed of 50 mph and a range of 40 miles at a speed of 40 mph. Heating and defrosting were accomplished with a gas heater and the recharge time was 10 hours. The Present Several legislative and regulatory actions in the United States and worldwide have renewed electric vehicle development efforts. Primary among these is the U.S. 1990 Clean Air Act Amendment, the U.S. 1992 Energy Policy Act, and regulations issued by the California Air Resources Board (CRAB). In addition to more stringent air emissions requirements and regulations requiring reductions in gasoline use, several states have issued Zero Emission Vehicle requirements. Electric conversions of gasoline powered vehicles, as well as electric vehicles designed from the ground up, are now available that reach super highway speeds with ranges of 50 to 150 miles between recharging.