Intermediate 1 Physics

Intermediate 1 Physics Electronics • Input, Process and Output • Digital Logic Gates Beath High School - Int 1 Physics

Intermediate 1 Physics Electronics Input, Process and Output Beath High School - Int 1 Physics

Input, Process and Output Electronic Systems When something is made up of lots of parts which are put together to do a job, it is called a s _ _ _ _ _ .When the parts are electronic components the system is called an e _ _ _ _ _ _ _ _ _ system. system. electronic Beath High School - Int 1 Physics

Electronic Systems Electronic systems can do lots of jobs.The type of job will depend on the components used to make the s _ _ _ _ _ .A calculator is an example of an electronic system.Every electronic system has t _ _ _ _ main sections - called sub-systems.These are called the i _ _ _ _ , the p _ _ _ _ _ _ and the o_ _ _ _ _. system. three input, process output. Beath High School - Int 1 Physics

Subsystem - Input What It Does Detects some type of e _ _ _ _ _ .(for example: light, heat, sound) and changes it to e _ _ _ _ _ _ _ _ _ energy.This is then passed to the p _ _ _ _ _ _ subsystem energy. electrical process Beath High School - Int 1 Physics

Subsystem - Process What It Does Changes the electrical energy from the i _ _ _ _ so that the system can do its job. This is then passed on to the o _ _ _ _ _ subsystem. input output Beath High School - Int 1 Physics

Subsystem - Output What It Does Converts the electrical e _ _ _ _ _ from theprocess subsystem into another type of energy which can be used. For example: h _ _ _ , l _ _ _ _ ,m _ _ _ _ _ _ _ energy heat, light, movement. Beath High School - Int 1 Physics

Block Diagrams A block diagram is an easy way to draw a system. Instead of drawing a complicated diagram showing all the components, we draw a box or b _ _ _ _ to take the place of the i _ _ _ _ , p _ _ _ _ _ _ and o _ _ _ _ _ subsystems.Each block is labelled so that we k _ _ _ what it is. block output input, process know Beath High School - Int 1 Physics

Block Diagrams The block diagram for a calculator is shown above. Any subsystem can be further broken down to smaller and smaller subsystems - down to the actual components if required. Beath High School - Int 1 Physics

Block Diagram Examples Public Address System microphone loudspeaker amplifier Beath High School - Int 1 Physics

Block Diagram Examples Smoke Alarm Output Input Process buzzer Beath High School - Int 1 Physics

Block Diagram Examples Intruder Lamp Heat Sensor lamp Beath High School - Int 1 Physics

Input and Output Devices energy Input subsystems contain a device which changes some form of e _ _ _ _ _ into electrical energy.Output subsystems contain a device which changes e _ _ _ _ _ _ _ _ _ e _ _ _ _ _ into some other form. energy electrical Beath High School - Int 1 Physics

Input Devices What it looks like: Device: microphone Circuit Symbol: How it Works: The inside of the microphone v_ _ _ _ _ _ _ exactly the same way as the sound waves. This makes identical electrical waves. vibrates Beath High School - Int 1 Physics

Input Devices What it looks like: Device: thermistor Circuit Symbol: How it Works: The resistance of the thermistor changes as the t_ _ _ _ _ _ _ _ _ _ _ changes. temperature Beath High School - Int 1 Physics

Input Devices What it looks like: Device: Light Dependent Resistor Circuit Symbol: How it Works: The resistance of the LDR decreases as the light level gets b_ _ _ _ _ _ _ . brighter. Beath High School - Int 1 Physics

Input Devices What it looks like: Device: switch Circuit Symbol: How it Works: Moving the switch from one setting to the other makes or b_ _ _ _ _ the circuit. breaks Beath High School - Int 1 Physics

Output Devices What it looks like: Device: loudspeaker Circuit Symbol: How it Works: Electrical energy -> Sound energy Electrical waves make vibrations inside the loudspeaker producing sound waves Beath High School - Int 1 Physics

Output Devices What it looks like: Device: buzzer Circuit Symbol: How it Works: Electrical energy -> Sound energy A voltage across the buzzer makes it sound. The buzzer just switches sound on or off. Beath High School - Int 1 Physics

Output Devices What it looks like: Device: lamp Circuit Symbol: How it Works: Electrical energy -> Light energy A voltage across the lamp makes it light. The greater the voltage, the brighter it gets. Beath High School - Int 1 Physics

Output Devices What it looks like: Device: Light emitting diode Circuit Symbol: How it Works: Electrical energy -> Light energy A voltage across the LED makes it light. LEDs are used to indicate when something is on or off. Beath High School - Int 1 Physics

Output Devices What it looks like: Device: electric motor Circuit Symbol: How it Works: Electrical energy -> Kinetic energy A voltage across the motor makes it turn. The greater the voltage, the faster it turns. Beath High School - Int 1 Physics

Examples of input and output applications Reason Device The output should be s _ _ _ _ _ waves Output of radio Loudspeaker sound Application The LDR will change resistance when the brightness changes Input of an automatic lamp L _ _ LDR The thermistor will c_ _ _ _ _ resistance when the temperature changes Input of a heating controller Thermistor change turn The motor will t_ _ _ the blades of the fan. M _ _ _ _ Motor Output of fan Beath High School - Int 1 Physics

Intermediate 1 Physics Electronics Digital Logic Gates Beath High School - Int 1 Physics

Digital Signals off ‘low’ Digital signals are either on or o _ _ .An ‘off’ signal has a zero voltage (called ‘l _ _’ ).An ‘on’ signal has a non-zero voltage(called ‘h _ _ _’ ).The ‘o _ _’ signal; low state is given the name ‘logic 0’ (most often just ‘0’). The ‘o _’ signal; high state is given the name ‘logic 1’ (most often just ‘ 1’). ‘high’ ‘off’ ‘on’ Beath High School - Int 1 Physics

Digital Signals 1 High voltage: Logic _ An oscilloscope can show logic states since it measures the high and low voltages. Oscilloscope trace showing a digital logicsignal which is changing from 1 to 0several times. Low voltage: Logic _ 0 Beath High School - Int 1 Physics

Logic Gates Digital logic gates are used to combine or change digital electronic signals. There are three basic types of logic gate called the N _ _ gate (sometimes called an i _ _ _ _ _ _ _ ), the A _ _ gate and the O _ gate. NOT inverter AND OR Beath High School - Int 1 Physics

The NOT gate This is the simplest gate. It has o _ _ input and o _ _ output.The output is always the opposite of the i _ _ _ _ . one one input. Beath High School - Int 1 Physics

NOT gate (Inverter) Symbol Logic Gate NOT Truth table How it behaves The NOT gate changes the input signal to the opposite state. Input Output High Low (0) (1) High Low (0) (1) Beath High School - Int 1 Physics

The AND gate The AND gate has two inputs and one output. The output of the AND gate is always at logic 0 unless both the inputs are at logic 1 when the output becomes logic 1 as well. Beath High School - Int 1 Physics

AND gate AND Truth table Output Input B Input A Symbol Low Low Low Logic Gate (0) (0) (0) High Low Low (0) (0) (1) How it behaves Low High Low The AND gate combines the input signals so that the output is only 1 when both inputs are 1. (0) (0) (1) High High High (1) (1) (1) Beath High School - Int 1 Physics

The OR gate The OR gate has two inputs and one output. The output of the OR gate is always at logic 1 unless both the inputs are at logic 0 when the output becomes logic 0 as well. Beath High School - Int 1 Physics

OR gate OR Truth table Output Input B Input A Symbol Low Low Low Logic Gate (0) (0) (0) High Low High (0) (1) (1) How it behaves Low High High The OR gate combines the input signals so that the output is 1 when either input is 1. (1) (0) (1) High High High (1) (1) (1) Beath High School - Int 1 Physics

Logical solutions 1. Donnie's dad wants to be wakened if he gets up at night. Design a system to sound a buzzer if Donnie switches on his light or if he stands on a mat. (A switch is under the mat.) Beath High School - Int 1 Physics

Buzzer Light sensor switch Solution System Diagram Beath High School - Int 1 Physics

Switch Light Sensor Open Dark Closed Light high high low low How it Works high. When the light is turned on, the light sensor output is h _ _ _ . This causes the OR gate output to go high which sounds the b _ _ _ _ _ . buzzer. When the switch under the mat is pressed, it c _ _ _ _ _ _ . This makes its output h _ _ _ .This causes the OR gate output to go h _ _ _ which sounds the buzzer. closes. high. high Beath High School - Int 1 Physics

2. A tomato grower wants to protect his delicate plants which are in his greenhouse. Design a warning system to sound a buzzer if it gets too cold during the night (dark). Beath High School - Int 1 Physics

Buzzer Light sensor Temperature sensor Solution System Diagram Beath High School - Int 1 Physics

Light Sensor Temperature Sensor Cold Dark Warm Light high high low low How it Works high. The buzzer can only switch on when the output from the NOT gate is h _ _ _ .Therefore the output from the OR gate must be l _ _ . low. The OR gate output can only be low if b _ _ _ the inputs are low. This means it must be both d _ _ _ and c _ _ _ as well.. both dark cold Beath High School - Int 1 Physics

Grandad can't use the stair light switch easily since he got his walking stick. Design a system which will switch on the stair light automatically when it gets dark. There must be a manual switch as well. Beath High School - Int 1 Physics

Lamp Light sensor switch Solution System Diagram Beath High School - Int 1 Physics

Light Sensor Switch Dark Open Light Closed high high low low How it Works high When it is dark, the light sensor output is low which is changed to h _ _ _ by the NOT gate. This causes the OR gate output to go high which l _ _ _ _ _ the lamp. lights When the switch is closed, its output is high. This causes the OR gate output to go h _ _ _ which lights the lamp.. high Beath High School - Int 1 Physics

4. Design a system for a bathroom to switch on a fan motor when the bathroom gets so steamy, the light from the window is blocked. The fan must only come on when it is hot as well as steamy. Beath High School - Int 1 Physics

Motor Light sensor Temperature sensor Solution System Diagram Beath High School - Int 1 Physics

Light Sensor Temperature sensor Cold Dark Warm Light high high low low How it Works low NOT When it is steamy, it gets darker, the light sensor output is l _ _ which is changed to high by the N _ _ gate.When it gets too h _ _ the output from the temperature sensor is h _ _ _ . hot high. Only when it is hot and steamy at the s _ _ _ time will both inputs of the AND gate be high to make the output high to t _ _ _ the motor.. same turn Beath High School - Int 1 Physics

Intermediate 1 Physics Electronics End of Unit Beath High School - Int 1 Physics

Intermediate 1 Physics