1. Chapter 4 Calculators for Electricity and Electronics

2. Introduction This chapter covers the following topics: Types of calculators Calculator requirements for electricity and electronics Using the calculator for electricity and electronics

3. Types of Calculators Scientific calculators –Include formulas and functions used in trigonometry and statistics Graphing calculators –Display graphs –Programmable

4. Figure 4-1 Examples of graphing calculators from the more popular calculator manufacturers. © 2014 Cengage Learning.

5. Types of Calculators (cont’d.) Criteria for calculator selection : Cost Documentation Durability Ease of Use Features Support

6. Figure 4-4 One of Texas Instruments’ graphing calculators, which can interface with the computer. © 2014 Cengage Learning.

7. Types of Calculators (cont’d.) Reverse polish notation (RPN) –Convenient method to enter formulas as algebraic equations –Uses “stacks” –Easy to implement and very fast Scientific calculators –Used to solve physics, math, and engineering problems

8. Calculator Requirements for Electricity and Electronics Calculator functions are most useful for this book –Plus, minus, times, divided by, inverse, square, and square root Know the sequence for entering data into calculator

9. Calculator Requirements for Electronics (cont’d.) Use the proper keystroke sequence to apply a formula Store and recall values in memory Calculate using exponents, reciprocals, powers, and roots Determine trigonometric functions of a given phase relationship

10. Using the Calculator for Electricity and Electronics Must understand mathematical principles: –To correctly enter data –To obtain correct answer Example 1: addition –Problem: add 39,857 and 19,733 –Solution: enter 39857, then press +, then 19733, then press =

11. Using the Calculator for Electronics (cont’d.) Example 2: subtraction –Problem: subtract 15,249 from 30,102 –Solution: enter 30102, then press -, then 15249, then press = Example 3: multiplication –Problem: multiply 33,545 by 981 –Solution: enter 33545, then press X, then 981, then press =

12. Using the Calculator for Electronics (cont’d.) Example 4: division –Problem: divide 36,980 by 43 –Solution: enter 36980, then press ÷, then 43, then press = Example 5: square root –Problem: find the square root of 35,721 –Solution: enter 35721, then press √

13. Total Resistance (Parallel Circuit)

14. Total Resistance (cont’d.) Example 6: Calculate the total equivalent resistance of the parallel circuit on page 38 of text

15. Total Resistance (cont’d.) Example 6 solution : Take reciprocal of R 1 : Enter 15, press 1/X Display shows 0.0666667 Take reciprocal of R 2 : Enter 27, press 1/X Display shows 0.037037 Take reciprocal of R 3 : Enter 33, press 1/X Display shows 0.030303 Take reciprocal of R 4 : Enter 47, press 1/X Display shows 0.0212766

16. Total Resistance (cont’d.) Example 6 solution (cont’d.) Add 0.0666667 and 0.037037 and 0.030303 and 0.0212766 Total equals 0.1552833 Take reciprocal of 0.1552833 Answer is 6.4398425 Round answer to 6.44 Ω

17. Total Resistance (cont’d.) Calculator with memory function allows solving without re-entering values –See Example 7 in the text for process

18. Rounding Rounding is not a calculator function –Must be done manually Drop the least significant digits until the desired number of digits remains Rounding rules –If number is less than five, the new least significant digit is not changed

19. Rounding (cont’d.) Rounding rules (cont’d.) If number is greater than five, increase the new significant digit by one If highest significant digit dropped equals five: –Increase the new significant digit if it is odd –Do not change the new significant digit if it is even

20. Rounding (cont’d.) Example 8: round 352.580 To the nearest tenth: 352.6 To the nearest whole number: 352 To the nearest hundred: 400