Cybernetics and Computers Chapter 17 Lesson 1

Cybernetics Study of how electrical-mechanical devices can duplicate the action of the human body Comparing the human body to a computer system is an easy way to explain this subject

Cybernetics

The Nervous System Uses chemical-electrical signals to control the body If you touch a sharp needle, nerve cells in your finger “fire” and send a signal through a strand of nerve cells in your hand, up your arm, and into your brain Nerve cells in your finger are comparable to a sensor, or input device, in a computer system

The Brain Uses billions of cells interconnected by linking cells called neurons When the brain “thinks”, minute electrical impulses travel from neuron to neuron Cells in the brain can be either charged (on) or not charged (off)

The Brain By connecting all the brain cells, the brain can decide what to do in each situation Computers produce logical outputs in a similar fashion

The Reflex Action Specific brain cells are activated by the needle prick (pain) signal, and a reflex output is produced The brain sends a signal to your arm to pull back This is similar to the action of an actuator, or output device, in a car’s computer system

Computer Complex electronic device that will produce programmed electrical output signals after receiving specific electrical input signals Computers monitor and control all major systems of a modern vehicle

Computer Advantages There are several reasons that computers are being used in modern vehicles Computers can provide several advantages

Computer Advantages Fewer moving parts to wear and go out of calibration Reduced fuel consumption Lower emissions Increased engine power Reduced vehicle weight

Computer Advantages On-board diagnostics Increased driver convenience Improved passenger safety Compensation for component wear

Binary Numbering System Uses only two numbers, zero and one Key to how computers operate Zero (0) and one (1) can be arranged in different sequences to represent other numbers, letters, words, an input, an output, or a condition

Binary Numbering System To use the binary system, a computer turns switches (transistors) on or off Off represents zero On represents one

Binary Numbering System

Binary Language A single zero or a one is called a bit Four bits make a nibble Eight bits make a byte or word

Gating Circuits Gate Common gate types: electronic circuit that produces a specific output voltage for given input voltages Common gate types: NOT AND NAND OR NOR

“Thinking” with Gates If an AND gate is compared to two switches wired in series, both switches must be on to activate the starter motor