Logic Gates Circuits in Cars

Automatic Headlights System

On most modern cars, the car can automatically turn the lights on and off when it detects it is driven at night time or when the driver is driving in rainy conditions. Nowadays most cars are equipped with the following sensors and switches to control the headlights:

• A light sensor that detects when it is day time. A light sensor would be “on” (1) when there is light outside, but would automatically turn off (0) when it is dark outside (night time or driving through a tunnel).
• A humidity sensor that detects when it is raining. A humidity sensor would be “on” (1) when it is raining outside, but automatically turns off (0) when is dry outside.
• A engine switch to turn the engine on (1) or off (0).
• A light switch to turn the lights on (1) or off (0).

Your task is a to design and test a logic gates circuit for the automatic headlights system that will apply the following rules:

• The headlights are on if the engine is on and it is dark outside
• The headlights are on if the engine is on and it is rainy outside
• The headlights are on if the light switch is turned on (even when the engine is off)
• If none of the above conditions are met, the headlights are turned off

Interior Light System

The interior light system (aka dome light) is used to lit up the inside of the car. The light is located on the ceiling of the car and can be manually turned on and off using a light switch located next to the light. Most cars are also equipped with sensors on each door. These sensors are on (1) when the door is open and off when the door is closed (0). Each door has its own sensor, including the driver door, the passenger door and the door to access the boot.

Your task is a to design and test a logic gates circuit for the interior light system that will apply the following rules:

• The interior light is on if the light switch is on
• The interior light is on if at least one of the door is open (on driver the driver side, passenger side or the door for the boot)
• If none of the above conditions are met, the interior light is turned off

Automatic windscreen wipers system

The windscreen wipers system is used to automatically detect when the screen wipers should be turned on to improve the driving condition/visibility of the driver when it’s raining. They rely on a humidity sensor located on the windscreen that is on (1) when it detects water/rain. The windscreen wipers can also be turned on manually using a switch on the dashboard of the car.

Your task is a to design and test a logic gates circuit for the automatic windscreen wipers system that will apply the following rules:

• The wipers are turned on if the engine is on and the humidity sensors detects rain water on the windscreen
• The wipers are turned on if the engine is on and the driver has turned the wipers switch on
• If none of the above conditions are met, the windscreen wipers are turned off

Dashboard Seatbelts Indicator

On the dashboard of this two-seater sports car, a light indicator is used to indicate if either the driver (D.) or the passenger (P.) (or both) have not locked their seatbelts.

The car uses weight/pressure sensors underneath each seat to detect if the seat is occupied (sensor on) or not (sensor off).
Each seatbelt has a locking mechanism with a sensor to detect if the seatbelt is on or off.

Design and test a logic gates circuit to control the seatbelt light indicator on the dashboard of the car.