Post on 24-Dec-2015
Implementing Logic Using Electronic circuits
“This endless circulation of theelectric fluid may appear paradoxical,But it is no less true and real, and you may feel it with your hands.”
Allessandro Volta 1745-1827
Electric Circuits
Ohm's Law:
IV
R
Power in an electrical circuitWhere:P is power in wattsV is voltage in voltsI is current in ampers
Where:I is current in ampers,V is voltage in voltsR is resistance in ohms ()
Where:I is current in ampers,V is voltage in voltsR is resistance in ohms ()
Power in an electrical circuit
P V I Where:P is power in wattsV is voltage in voltsI is current in ampers
Electric Circuits Switch Logic
Switch open = input logic state 0 Switch closed = input logic state1 Lamp off = output logic state 0 Lamp on = output logic state1
OR analogue circuit
• Lamp L off (state 0) unless either A or B closed•This is an OR operation.
Can you draw a circuit with an AND operation?
A B
L
NOR (not or) Logic Function
Switch not pressed = input logic state 0Switch pressed = input logic state 1Lamp off = output logic state 0Lamp on = output logic state 1
Input A Input B
Output
Relay NOR Circuit
• Relay coil not energized = input logic state 0•Relay coil energized = input logic state1•Lamp off = output logic state 0•Lamp on = output logic state1
A input B input
Battery
Transistor NOR Circuit
Input A Input B
Battery
Output
•Gate Voltage 0 volts = input logic state 0
•Gate Voltage 5 volts = input logic state 1
•Output Voltage 0 volts = output state 0
•Output Voltage 5 volts = output state 1
Integrated Circuits
Only 7/16" wide and containing two transistors, this unassuming integrated circuit was nevertheless the first. It was mounted on a bar of germanium and was demonstrated by TI on September 12, 1958.
Complex Integrated Circuits
Millions of transistors can be combined on a single chip to create a Central processing Unit
Integrated Circuits can be fabricated to act as storage for program instructions and data.
THE CPU The CPU (Central Processing
Unit) is the complex integrated circuit that makes something a computer.
The CPU is the part of the computer that processes information, performs arithmetic calculations, and makes decisions based on information values.
The instructions and information used by the CPU are stored in computer memory.
CPUProcessorInput
PermanentStorage
Output
TemporaryStorage
Intel 4004 chipIntel 4004 chip
The Hardware/Software Connection
The hardware consists of the physical part of the computer: CPU chips, RAM and ROM chips
The software is the program instructions used by the CPU chip.
The hardware function of the computer can be changed by changing the software.
Embedded Systems
An embedded computer is a special purpose computer frequently used to control hardware devices.
Examples: microwave oven, automobile engine control computer.
Examples of Embedded Systems
Personal items such as personal digital assistants (PDAs), mp3 players, mobile phones, videogame consoles, digital cameras, DVD players, GPS receivers, and printers.
Many household appliances, such as microwave ovens, washing machines and dishwashers, are including embedded systems to provide flexibility, efficiency and features.
Advanced HVAC systems use networked thermostats to more accurately and efficiently control temperature that can change by time of day and season.
Home automation uses wired- and wireless-networking that can be used to control lights, climate, security, audio/visual, etc., all of which use embedded devices for sensing and controlling.
Computers in CarsAll cars manufactured today contain at least one computer. It is in charge of monitoring engine emissions and adjusting the engine to keep emissions as low as possible. The computer receives information from a many different sensors, including: The oxygen sensor The air pressure sensor The air temperature sensor The engine temperature sensor The throttle position sensor The knock sensor The oxygen sensor
Computers in CarsDepending on how expensive your car is, there can be all sorts of other computers. For example:
There is probably a computer controlling the automatic transmission
If the car has anti-lock brakes, there is a computer reading the wheel speed and controlling the brakes
Many air bag systems have their own computers A car with keyless entry or a security system has a computer for
these systems Advanced climate control systems often have computers Some cars now have motorized seats and mirrors that can
remember the settings for multiple drivers, and these contain computers
Any radio or CD player with a digital display contains a computer of its own
Cruise control systems use computers
Embedded Computers in Cars
SPEECH TECHNOLOGY LIGHTING SYSTEM ELECTRONIC-MEMORY SEAT ELECTRIC WINDOWS MIRROR CONTROL PREMIUM AUDIO SYSTEM DOOR MODULE CLIMATE CONTROL VEHICLE-T0-ROADSIDE
COMMUNICATIONS RAIN SENSOR ONE-WAY DATA PAGER DIGITAL RADIO HIGH-INTENSITY DISCHARGE
LAMPS NAVIGATION/GPS
ALARM SYSTEMS TRIP COMPUTER HEAD-UP DISPLAY ANALOG AND DIGITAL
INSTRUMENTATION RIGHT-OF-CLUSTER DISPLAY CRUISE CONTROL INTERNET INTEGRATED CELL PHONE CENTRAL-BODY CONTROLLERS CENTRAL LOCKING REMOTE KEYLESS ENTRY TRANSMISSON CONTROLLER
ENGINE CONTROLLER IMMOBILIZATION
Future Cars Future car technology is now wide open. For instance, with
peak oil looming and future shortages of fossil fuels imminent there has been much emphasis lately on cars that run on alternative fuels.
In the longer term, future car technology will most likely involve cars that run on hydrogen, electricity, air, nitrogen, or even nuclear power.
In 1958 the first nuclear automobile was the Ford Nucleon. The Ford Nucleon was a concept vehicle that was supposed to be powered by a small nuclear reactor at the rear of the vehicle fueled by radioactive material. No working prototypes were ever built.