Introduction to Engineering Electronics: Concepts and Applications

1. Lecture 5 Binary Counter Thinking Digitally Introduction to Engineering Electronics K. A. Connor

2. Henry Farny’s Song of the Talking Wire Introduction to Engineering Electronics K. A. Connor

3. 2 Minute QuizName_________________ Sec____ • Code Example: • Code Example: • Code Example: • PWM Question: Introduction to Engineering Electronics K. A. Connor

4. Joseph Henry & the Telegraph • Albany Academy Experiment • Assisted Morse at Princeton • 1st Head of Smithsonian • Unit of inductance: Henry Introduction to Engineering Electronics K. A. Connor

5. Morse Code • Simple sequences of short and long clicks to represent letters and numbers • Easier to generate than sound • Easier to distinguish than sound Introduction to Engineering Electronics K. A. Connor

6. UPC Codes • Bars come in four widths 1-2-3-4 • Start is 1-1-1 (black-white-black) • 0 = 3-2-1-1 • 1 = 2-2-2-1 • 2 = 2-1-2-2 • 3 = 1-4-1-1 • 4 = 1-1-3-2 • 5 = 1-2-3-1 • 6 = 1-1-1-4 • 7 = 1-3-1-2 • 8 = 1-2-1-3 • 9 = 3-1-1-2 • The zero is 3-2-1-1 (space-bar-space-bar). • The four is 1-1-3-2 (space-bar-space-bar). • The three is 1-4-1-1 (space-bar-space-bar). • The next three zeros are 3-2-1-1 (space-bar-space-bar). • In the middle there is a standard 1-1-1-1-1 (space-bar-space-bar-space), which is important because it means the numbers on the right are optically inverted! • The one is 2-2-2-1 (bar-space-bar-space). • … • The stop character is a 1-1-1 (bar-space-bar). Introduction to Engineering Electronics K. A. Connor

7. Computer Number System ExamplesFrom Computer Science I 10110101110001011001110011110110 binary number 11 5 12 5 9 12 15 6 equivalent base 10 value for each group of 4 consecutive binary digits (bits) B 5 C 5 9 C F 6 corresponding hexadecimal (base 16) digit B5C59CF6 equivalent hexadecimal number Introduction to Engineering Electronics K. A. Connor

8. Communicating With Pulses • PCM: Pulse Code Modulation Introduction to Engineering Electronics K. A. Connor

9. PCM: Pulse Code Modulation Introduction to Engineering Electronics K. A. Connor

10. PWM: Pulse Width Modulation • Signal is compared to a sawtooth wave producing a pulse width proportional to amplitude Introduction to Engineering Electronics K. A. Connor

11. Optical Receiver • Receiver detects pulses of light • Pulses are amplified and partly averaged by 741 op-amp (volume adjusted with the pot) • Higher frequencies still in signal cannot be heard • Signal is increased by 386 audio amp • 386 audio amp drives the speaker Introduction to Engineering Electronics K. A. Connor

12. Optical Transmitter • Audio signal changes thresholds for 555 timer producing a type of pulse width modulation of the light from the LED. Introduction to Engineering Electronics K. A. Connor

13. Signals from Audio Remote Mostly hear higher frequencies in pulses 3.5 x 20 = 70ms or 14Hz 2 x 100 / 9 = 23us or 43kHz 4 x 500 = 2000us or 500Hz Introduction to Engineering Electronics K. A. Connor

14. Binary Numbers 0 0000 1 0001 2 0010 3 0011 4 0100 5 0101 6 0110 7 0111 8 1000 9 1001 10 1010 11 1011 128 + 0 + 32 + 16 + 0 + 4 + 2 + 1 = 183 Introduction to Engineering Electronics K. A. Connor

15. Binary Counter • Animations showing counter operation http://www.play-hookey.com/digital/synchronous_counter.html • Counter for lab Introduction to Engineering Electronics K. A. Connor

16. Typical Output for Binary Counter • Note how the Q outputs form 4 bit numbers Introduction to Engineering Electronics K. A. Connor

17. Digital Pulses • Function generator produces a 1kHz sinusoidal voltage. 1v peak-to-peak (pp) Introduction to Engineering Electronics K. A. Connor

18. Digital Pulses • Switch to a square wave at 1kHz. Still 1v pp Introduction to Engineering Electronics K. A. Connor

19. Digital Pulses • Add a 0.5 volt offset so that the square wave goes from 0 volts to 1 volt Introduction to Engineering Electronics K. A. Connor

20. Digital Pulses • Now the duty cycle is adjusted to 20% to see what a single digital pulse looks like. Introduction to Engineering Electronics K. A. Connor

21. Pulses on a Transmission Line • Pulses propagate down transmission lines at the speed of light. They reflect off of the load if the load is not the same impedance as the line. Lines, sources and loads must be matched. • Cable TV lines are 75 ohms. Cables in the lab are typically 50 ohms. From Matlab Introduction to Engineering Electronics K. A. Connor

22. What Can Be Done With PWM? Low Duty Cycle • Question: What happens if voltages like the ones above are connected to a light bulb? (4th 2 Minute Quiz Question) • Answer: The longer the duty cycle, the longer the light bulb is on and the brighter the light. Medium Duty Cycle High Duty Cycle Introduction to Engineering Electronics K. A. Connor

23. What Can Be Done With PWM? • Average power can be controlled • Average flows can also be controlled by fully opening and closing a valve with some duty cycle Introduction to Engineering Electronics K. A. Connor

24. What About Analog Modulation? • AM: Amplitude Modulation • FM: Frequency Modulation Introduction to Engineering Electronics K. A. Connor

25. Other Coding Applications • Cryptography • Image Compression • JPEG (Joint Photographic Expert Group) • GIF (Graphics Interchange Format) • TIFF (Tagged Image File Format) • MPEG (Compression of Motion Video) • Most use Discrete Cosine Transform method Introduction to Engineering Electronics K. A. Connor

26. Image Compression 2 bpp 0.5 bpp 24 bpp original (bits per pixel) Top: JPEG Bottom: JPEG2K Introduction to Engineering Electronics K. A. Connor

27. Where Will You See This Material Again? • 555 Timer – IEE Lab 6 • Digital Counter – IEE Lab 7 • Counters: ECSE- 2610 Computer Components and Operations, ENGR-2350 Introduction to Embedded Control • Signals and Transforms: ECSE-2410 Signals and Systems • Pulse Width Modulation: Embedded Control, ECSE/EPOW-4080 Semiconductor Power Electronics • Pulses on Transmission Lines: ECSE-2100 Fields and Waves I Introduction to Engineering Electronics K. A. Connor