Technological Studies Data Booklet Higher

Transcription

1

2 Technological Studies Data Booklet Higher For use in National Qualification Courses leading to the 009 examinations and beyond. Published date: July 008 Publication code: BB4470 ISBN: Published by the Scottish Qualifications Authority The Optima Building, 8 obertson Street, Glasgow G 8DQ Ironmills oad, Dalkeith, Midlothian EH 1LE The information in this publication may be reproduced in support of SQA qualifications. If it is reproduced, SQA should be clearly acknowledged as the source. If it is to be used for any other purpose, then written permission must be obtained from the Publishing Team at SQA. It must not be reproduced for trade or commercial purposes. Scottish Qualifications Authority 008

3 For an up-to-date list of prices visit the Publication Sales and Downloads section of SQA s website. This document can be produced, on request, in alternative formats, including large type, braille and numerous community languages. For further details telephone SQA s Customer Contact Centre on

4 Contents Preface 1 Basic Units and Decimal Prefixes Applied Electronics Basic Equations Typical Operational Amplifier Circuits 4 Graphs for Thermistors, Thermocouple and LD 7 Systems and Control 10 Symbols for Flowcharts 10 Number Systems, PBASIC Instruction Set 11 Structures and Materials 1 Basic Formulae 1 Young s Modulus and Stress data 1

5

6 Preface This data booklet is intended for use by candidates in examinations in Technological Studies at Higher level. It is recommended that candidates should become familiar with the contents of the data booklet through use in undertaking units of these courses. It should be noted that the range of data contained in the booklet has been limited to that syllabus content which may be assessed through written examination papers. This range should be supplemented by other resource material as necessary during the course, eg by using data sheets. However, should any additional information (or data not included in this booklet) be required in an examination, such information will be included in the examination paper. Teachers/lecturers should note that all of the material contained in this booklet is likely to be examined at some time. With regard to tables of information, not every entry in a table will necessarily be involved in examination questions. From the variety of data offered in this booklet, candidates will be expected to demonstrate the ability to select an appropriate: item of information formula material property operational amplifier circuit PBASIC instruction 1

7 Basic Units and Decimal Prefixes Quantity Basic Units Symbol Unit Abbreviation Length l, L metre m Distance s, x metre m Time t second s Velocity v metre/second m/s Mass m kilogram kg Force F newton N Work W joule J Energy E joule J Power P watt (J/s) W Stress σ newton/metre N/m Strain ε no unit Temperature T, t kelvin, celsius K, C Current I ampere (amp) A Voltage V volt V esistance ohm Ω Frequency f hertz Hz Decimal Prefixes Prefix Symbol Multiplying Factor tera T 10 1 giga G 10 9 mega M 10 6 kilo k 10 milli m 10 micro μ 10 6 nano n 10 9 pico p 10 1

8 Applied Electronics Basic Equations Ohm s law V = I esistors in series T = esistors in parallel = + + T 1 for resistors in parallel T product + sum 1 = T = 1 Kirchhoff s 1st Law ΣI = 0 (Algebraic sum of currents at a node is zero) Kirchhoff s nd Law ΣE = ΣI (Algebraic sum of supply voltages = sum of voltage-drops, in a closed loop) Voltage Divider ule V1 1 = V (atio of Voltages = Corresponding atio of esistances) Electrical Power V P = VI= = I Bi-polar transistor gain h FE = I I c b MOSFET transconductance g m ΔI = Δ V D GS

9 Typical Operational Amplifier Circuits V o = output voltage V i = input voltage V cc = supply voltage f = feedback resistance i = input resistance Note: Op-amp output saturates at 8% of V cc A v output voltage = gain = input voltage Inverting f i +V cc V i V cc V o 0V A v = V V o i A v = f i V o = f i V i Non-inverting f +V cc 0V i V i V cc V o A v V ( V 1 f ) o f = A v = 1+ = + V Vi i o i i 4

10 Comparator +V cc V i V ref V cc Vo 0V If V i < V ref, then V o saturates positively (8% of +V cc ) If V i > V ref, then V o saturates negatively (8% of V cc ) Difference Amplifier f i +V cc i V cc Vo V 1 V f 0V A v = Vo (V V ) 1 A v = f i V = (V V) f o 1 i

11 Summing Amplifier f 1 +V cc V 1 V V cc V o 0V A = A = A = f f f v1 v vn 1 n V = (A V ) + (A V ) o v1 1 v ( ) V V Vo = f Voltage Follower +V cc V i V cc V o 0V V o = V i 6

12 Graphs for Thermistors, Thermocouple and LD Thermistors: esistance-temperature characteristics esistance (Ω) 10M 8 1M 8 100k 8 10k 8 1k Temperature ( C)

13 Thermocouple Typical temperature gradient for type K thermocouple Thermocouple emf (mv) Temperature difference ( C) 8

14 Light Dependent esistor (LD) 10 7 LD type OP1 Cell resistance (kω) Illumination (lux) 9

15 Systems and Control Symbols for Flowcharts Terminator symbol Used for the start and end of a main program or sub-procedure. Line symbol Indicates the direction of program flow. For flow down or to the right arrows are not needed. For flow upwards or to the left, arrows are added. Input/Output symbol Used to control outputs or to show that data is being received. Process symbol Used for operations which take place within the microcontroller. Decision symbol Program flow is determined by a yes or no answer to the question in the box. Sub-procedure symbol Used to call a sub-procedure. 10

16 Number Systems and PBASIC Instruction Set Number Systems Bit Number Binary Decimal The default number system is decimal. For binary numbers, the prefix symbol % is used. PBASIC Instruction Set Instruction symbol INPUT/OUTPUT high x low x dirs pins TIME pause n POGAM FLOW goto label gosub label return if then label for next end Make pin x an output and set it high Make pin x an output and set it low Set up each pin on POTB to input or output Control all pin states at once Create a time delay of n (0 6) milliseconds Jump to label Jump to sub-procedure at label eturn from sub-procedure If a condition is met, jump to a label (but not to a sub-procedure) Establish a loop which repeats a specified number of times End of program flow Explanation Allocate a name to a pin or variable Variables Byte variables (b0 b1) can store values 0. Word variables (w0 w) can store values 0 6; w0 contains b0 and b1 within it; w1 contains b and b within it etc. 11

17 Structures and Materials Basic Formulae Moment of a force M = Fx x is the perpendicular distance Principle of Moments ΣM = 0 Conditions of equilibrium ΣF h = 0 ΣF v = 0 ΣM = 0 Stress σ = F A Strain ε = Δl l Young s Modulus E σ = ε Factor of Safety ultimate load = = safe working load ultimate stress safe working stress Circumference of a circle = πr = πd Area of a circle = π r = πd 4 1

18 Young s Modulus and Stress Material Young s Modulus E kn/mm Yield Stress σ Y N/mm Ultimate Tensile Stress N/mm Ultimate Compressive Stress N/mm Mild steel Stainless steels Low-alloy steels Cast iron Aluminium alloy Soft brass Cast bronze Titanium alloy Nickel alloys Concrete 60 Concrete (steel reinforced) Concrete (post stressed) 100 Plastic, ABS polycarbonate Plastic, polypropylene Wood, parallel to grain Wood, perpendicular to grain Soda glass Diamond Gold Ice

19