1. Beath High School - Int 1 Physics1 Intermediate 1 Physics Electronics Input, Process and Output Digital Logic Gates

2. Beath High School - Int 1 Physics2 Intermediate 1 Physics Electronics Input, Process and Output

3. Beath High School - Int 1 Physics 3 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

4. Beath High School - Int 1 Physics 4 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.

5. Beath High School - Int 1 Physics 5 Subsystem - Input 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 What It Does

6. Beath High School - Int 1 Physics 6 Subsystem - Process 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 What It Does output

7. Beath High School - Int 1 Physics 7 Subsystem - Output Converts the electrical e _ _ _ _ _ from the process subsystem into another type of energy which can be used. For example: h _ _ _, l _ _ _ _, m _ _ _ _ _ _ _ energy heat, movement. What It Does light,

8. Beath High School - Int 1 Physics 8 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 input, process output know

9. Beath High School - Int 1 Physics 9 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.

10. Beath High School - Int 1 Physics 10 Block Diagram Examples Public Address System microphone amplifier loudspeaker

11. Beath High School - Int 1 Physics 11 Block Diagram Examples Smoke Alarm buzzer InputProcess Output

12. Beath High School - Int 1 Physics 12 Block Diagram Examples Intruder Lamp Heat Sensor lamp

13. Beath High School - Int 1 Physics 13 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. Input and Output Devices energy electrical energy

14. Beath High School - Int 1 Physics 14 How it Works: The inside of the microphone v_ _ _ _ _ _ _ exactly the same way as the sound waves. This makes identical electrical waves. Device: microphone Input Devices What it looks like: Circuit Symbol: vibrates

15. Beath High School - Int 1 Physics 15 How it Works: The resistance of the thermistor changes as the t_ _ _ _ _ _ _ _ _ _ _ changes. Device: thermistor Input Devices temperature What it looks like: Circuit Symbol:

16. Beath High School - Int 1 Physics 16 How it Works: The resistance of the LDR decreases as the light level gets b_ _ _ _ _ _ _. Device: Light Dependent Resistor Input Devices brighter. What it looks like: Circuit Symbol:

17. Beath High School - Int 1 Physics 17 How it Works: Moving the switch from one setting to the other makes or b_ _ _ _ _ the circuit. Device: switch Input Devices breaks What it looks like: Circuit Symbol:

18. Beath High School - Int 1 Physics 18 How it Works: Electrical energy -> Sound energy Electrical waves make vibrations inside the loudspeaker producing sound waves Device: loudspeaker Output Devices What it looks like: Circuit Symbol:

19. Beath High School - Int 1 Physics 19 How it Works: Electrical energy -> Sound energy A voltage across the buzzer makes it sound. The buzzer just switches sound on or off. Device: buzzer Output Devices What it looks like: Circuit Symbol:

20. Beath High School - Int 1 Physics 20 How it Works: Electrical energy -> Light energy A voltage across the lamp makes it light. The greater the voltage, the brighter it gets. Device: lamp Output Devices What it looks like: Circuit Symbol:

21. Beath High School - Int 1 Physics 21 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. Device: Light emitting diode Output Devices What it looks like: Circuit Symbol:

22. Beath High School - Int 1 Physics 22 How it Works: Electrical energy -> Kinetic energy A voltage across the motor makes it turn. The greater the voltage, the faster it turns. Device: electric motor Output Devices What it looks like: Circuit Symbol:

23. Beath High School - Int 1 Physics 23 Examples of input and output applications Application Output of radio Input of an automatic lamp Input of a heating controller Output of fan Device Loudspeaker L _ _ Thermistor M _ _ _ _ The output should be s _ _ _ _ _ waves Reason The LDR will change resistance when the brightness changes The thermistor will c_ _ _ _ _ resistance when the temperature changes The motor will t_ _ _ the blades of the fan. LDR sound change turn Motor

24. Beath High School - Int 1 Physics24 Intermediate 1 Physics Electronics Digital Logic Gates

25. Beath High School - Int 1 Physics 25 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’). Digital Signals off ‘low’ ‘high’ ‘off’ ‘on’

26. Beath High School - Int 1 Physics 26 High voltage: Logic _ An oscilloscope can show logic states since it measures the high and low voltages. Digital Signals 1 Low voltage: Logic _ Oscilloscope trace showing a digital logic signal which is changing from 1 to 0 several times. 0

27. Beath High School - Int 1 Physics 27 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. Logic Gates NOT inverter AND OR

28. Beath High School - Int 1 Physics 28 This is the simplest gate. It has o _ _ input and o _ _ output. The output is always the opposite of the i _ _ _ _. The NOT gate input. one

29. Beath High School - Int 1 Physics 29 The NOT gate changes the input signal to the opposite state. Logic Gate NOT gate (Inverter) Symbol How it behaves NOT Truth table Input Output High Low High (1) (0) (1)

30. Beath High School - Int 1 Physics 30 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. The AND gate

31. Beath High School - Int 1 Physics 31 The AND gate combines the input signals so that the output is only 1 when both inputs are 1. Logic Gate AND gate Symbol How it behaves AND Truth table Input A Output High Low High (1) (0) (1) Input B Low High (0) (1) Low (0) Low (0) High (1) Low (0)

32. Beath High School - Int 1 Physics 32 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. The OR gate

33. Beath High School - Int 1 Physics 33 The OR gate combines the input signals so that the output is 1 when either input is 1. Logic Gate OR gate Symbol How it behaves OR Truth table Input A Output High Low High (1) (0) (1) Input B Low High (0) (1) Low (0) High (1) High (1) High (1)

34. Beath High School - Int 1 Physics 34 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.) Logical solutions

35. Beath High School - Int 1 Physics 35 Solution System Diagram Light sensor switch Buzzer

36. Beath High School - Int 1 Physics 36 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 _ _ _ _ _. high. How it Works Light Sensor Dark Light low high Switch Open Closed low high 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. buzzer. closes. high. high

37. Beath High School - Int 1 Physics 37 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).

38. Beath High School - Int 1 Physics 38 Solution System Diagram Light sensor Temperature sensor Buzzer

39. Beath High School - Int 1 Physics 39 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 _ _. high. How it Works 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.. Light Sensor Dark Light low high Temperature Sensor Cold Warm low high low. both dark cold

40. Beath High School - Int 1 Physics 40 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.

41. Beath High School - Int 1 Physics 41 Solution System Diagram Light sensor Lamp switch

42. Beath High School - Int 1 Physics 42 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. high How it Works When the switch is closed, its output is high. This causes the OR gate output to go h _ _ _ which lights the lamp.. Light Sensor Dark Light low high Switch Open Closed low high lights high

43. Beath High School - Int 1 Physics 43 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.

44. Beath High School - Int 1 Physics 44 Solution System Diagram Light sensor Motor Temperature sensor

45. Beath High School - Int 1 Physics 45 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 _ _ _. low How it Works 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.. Light Sensor Dark Light low high Temperature sensor Cold Warm low high NOT high. hot same turn

46. Beath High School - Int 1 Physics46 Intermediate 1 Physics Electronics End of Unit