How an Electric Car Works

An electric car is powered by an electric motor unlike your traditional car motors which are powered by gasoline powered engines. When you look under the hood of an electric car, it is going to look a lot different than a gasoline powered motor, in that an electric car consists of many wires while a gasoline engine consists of many hoses, exhaust pipes and fuel lines.

An electric car uses a controller to tell it what to do. The controller is connected to the batteries and to the motor. When the driver puts his foot down on the accelerator, the controller sends volts of power to the engine. When the driver lifts his foot off of the accelerator, 0 volts of power are sent to the engine. Some cars use DC controllers, while other cars use AC controllers.

A potentiometer is connected to the accelerator foot pedal which sends signals to the controller telling it how much power to distribute from the batteries to the engine. For safety reasons, there are actually 2 potentiometers that compare with each other to ensure they are both reading the same. If the potentiometers do not read the same, the controller will not take any action.

The DC controller does not actually stay on the whole time you have the accelerator pedal pushed down. The DC controller actually sends over 15,000 pulses of power per second to the engine. A DC controlled motor may run on 96 to 192 volts. A DC controlled electric car is usually cheaper to buy than an AC controlled electric car.

The AC controller is different than that of a DC controller. The AC controller makes three pseudo-sine waves which takes the DC voltage and pulses it on and off. The AC controller uses six sets of transistors to reverse the polarity of the voltage. The polarity of the voltage is then reversed 60 times over the course of 1 second. An AC controlled motor usually runs at 240 volts AC using a 300 volt battery pack.

The power most electric cars get comes from a battery pack. These batteries are usually 1000 pounds or more in weight, very large, and only hold enough electricity to travel about 50 miles. The batteries will only last about 3 to 4 years and are very expensive to replace. These batteries also take several hours to recharge.

In closing, some day most people will probably be driving electric cars, but I think manufacturers still have a ways to go to get the electric cars perfected.