Sat Nav has been around long enough for most of us to figure out roughly how it works, right? Well if not, it goes like this. The sat nav device in your car communicates with a network of satellites orbiting the earth at an altitude of around 20,000km. By receiving signals from 3 or 4 satellites simultaneously, your device can triangulate its position to within a few metres. But how does it know when to send you an alternative route if the road ahead is congested?
Sat nav systems receive data from multiple sources, including other drivers’ mobile phones, speed cameras, and lots of other in-car sat navs. So when the ‘mother’ system detects lots of cars moving very slowly or stopping, it knows that traffic on that section of road is grinding to a halt, so it diverts you to another.
ABS stands for anti-lock braking system - which does exactly what it says on the tin. But how? And why? Well, ABS is all about helping to keep your car under control when braking hard. Just imagine… you’re driving a car without ABS and a pedestrian steps out in front of you. Your instinct is to slam on the brakes. But if you do, the wheels will lock up and you’ll go into a skid. To regain control of the steering, you have to ease off the brakes so the wheels can roll. But to do it effectively, you’d need to step on and off the brake pedal hundreds of times a second - which is basically what ABS does.
A sensor in each wheel detects the moment your tyres begin to lock up. The ABS momentarily eases off the brakes, allowing the tyres to retain traction. Then ABS reapplies the brake. Then releases it. And applies it. Hundreds of times a second. Faster than you can think. So, you can steer around the pedestrian instead of skidding into them.
Internal combustion engine
A car’s engine converts your fuel’s chemical energy into kinetic energy (or movement). And it does this through the process of combustion, or burning. Most car engines have four cylinders, each with a piston that fits snugly inside but that’s able to move up and down freely. In a petrol engine, fuel is injected into each cylinder in turn, and a spark from the sparkplug ignites the mixture of petrol and air to create an explosive expansion of combustion gases - forcing the piston up.
The piston is connected to a crankshaft which is rotated as the piston moves upwards. And the crankshaft is connected to a system of gears which drive the car’s wheels. Diesel engines are a little different (fuel is sprayed into the cylinder and ignited by the hot compressed air rather than a sparkplug), but the basic principle is exactly the same.