# 1. Produce a ladder diagram that will cause output Y to go HIGH when switch A and B are closed OR when switch C is closed. (Hint: Start with the Boolean equation). 2. Design the ladder diagram for a new Ford truck door/safety belt system. When the truck door is open and the seat belt is not clicked in, the truck will not start. If door is closed and seat belt is clicked in, the key will start the ignition. 3. Give ladder diagram to control a washing machine. This washing machine would have a fill cycle to one level, a 10 second wash cycle, a 10 second rinse cycle and then drain. Include a start button, low level switch, high level switch, an agitator motor, a fill valve and a drain valve. Designing Ladder Diagrams for Automotive Safety Systems

Automotive Safety Systems Design: Ladder Diagrams

A ladder diagram can be described as a type of graphic programming language for developing control systems. A ladder diagram is commonly used in automation and robotics for programming logic-based control systems, such as the car door/safety belt. The goal of this ladder diagram is to cause output Y TO go HIGH when switches A, B and C are shut. First, let’s look at the Boolean equation. This equation can be written as: Y = A*B + C (Ghahramani, 2019). The ladder diagram will have two input contacts (A, B), and one output (Y). If A and B are closed simultaneously, current flows from the input on the left to the output on the right. (Salomon 2020). This will cause output number Y to rise HIGH. The same thing happens when C is closed. Current will flow from the input contacts on the left to the output contacts on the right. This causes Y to go HIGH. For the Ford new truck doors/safety belt systems, the ladder diagram is slightly more complicated. It is important that the truck does not start if the door is opened and the seatbelt isn’t clicked in. This ladder diagram must have both the inputs (the seat belt and the door) as well as one output (the ignition). The ignition will not turn if the door is closed and the seatbelt has not been clicked in. Current will flow if you close the door and click in the seatbelt. Cont…