1 / 57

How to Build a Digital Physical System - Lab

Lecture 2. How to Build a Digital Physical System - Lab. Today's Topics. Electricity/Water analogy Electrical/Electronic circuit elements Basic formulae Useful conventions Reading and drawing schematics Using datasheets Test Equipment Practical – Wire stripping and Soldering.

rebecca
Download Presentation

How to Build a Digital Physical System - Lab

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Lecture 2 How to Build a Digital Physical System - Lab

  2. Today's Topics • Electricity/Water analogy • Electrical/Electronic circuit elements • Basic formulae • Useful conventions • Reading and drawing schematics • Using datasheets • Test Equipment • Practical – Wire stripping and Soldering

  3. The following entities between a water circulation system and an electric circuit correspond fairly well Pressure – Voltage Water flow – Current Gate valve, Constriction – Resistance Valve – Switch One way valve – Diode etc... Water Analogy

  4. Comparisons

  5. Circuit Elements • Power supply • Resistors • Capacitors • Inductors • Semiconductors

  6. Circuit Elements • Power supply • Energy source • Unit - Volts

  7. Circuit Elements • Resistor, Capacitors and Inductors • Passive components

  8. Resistors • Control current, dissipate energy as heat • Unit – Ohms • Symbol

  9. Resistor Color Code Black Bears Raid Our Yellow Grain, Blue Violets Grow Wild

  10. Capacitors and Inductors • Energy storage elements • Used in filters

  11. Filters

  12. Circuit Elements • Semiconductors • Active devices • Transistors, ICs, LEDs, gates, diodes

  13. Diodes • Allow current flow in one direction only • Rectification – change AC to DC

  14. LEDs • Diodes that produce light

  15. Transistors • Amplification, switching

  16. Circuit Elements • Subgroup of ICs • Microcontrollers (pic, Atmega etc.) • Microcontroller development boards • Arduino

  17. Types of Circuits • Analog • Continuous values of voltage between Ground and Power • Digital • Only On or Off, High or Low, or Ground or Power • Hybrid

  18. Datasheets • Your crucial companion • Consult the manufacturer's datasheet if unsure of a device's specific behaviour • Of special interest • Pinouts • Absolute maximum ratings • Typical application circuit

  19. Important sections

  20. Typical Circuit

  21. Pinouts

  22. Features

  23. Examples • Analog • Most sensors, the physical world • Digital • Your computer, most modern devices, your iPod for the most part

  24. Schematics • Symbolic representation of a circuit

  25. Schematic • More complex circuit

  26. Useful Conventions • Make your schematics and breadboards easier to understand and troubleshoot for yourself and others • Learn to work like the pros

  27. Conventions • Wiring colors on breadboards Red for power Black for ground Others as needed, for example, inputs yellow outputs green etc. • Schematic layout Maintain left to right signal flow Inputs on the left, outputs on the right(device & page) Power to top of page, ground to bottom

  28. Some Common Formulas • Ohm's law • E = V = IR • Formula wheel • E - (emf) same as Voltage • R – resistance • I – current • P - power

  29. Circuits and Ohm's Law • For resistive circuits

  30. Series and Parallel Circuits

  31. Series and Parallel Circuits • Series circuit • Same current, voltage divides • Parallel circuit • Same voltage, current divides

  32. Using Ohm's Law • Equivalent resistance = 1470ohms

  33. Illustration on Board

  34. Series Example

  35. Parallel Example

  36. Our First Circuit • Using an LED • Determine the resistor value • Use a switch to activate the circuit

  37. Components • Battery(power supply) • Resistor • LED • Switch

  38. Functions • Battery to power circuit • LED to produce the light • Resistor to control circuit current suitable for the LED • Switch to turn the circuit 'on'

  39. Draw Schematic

  40. Determine Values • LED rated for 11mA(milliampere) forward current at 2V (volts) • For a 5V battery power and 2V across the LED the remaining 3V need to appear across the resistor • Since LED is rated at 11mA(0.011A) and is in series with resistor, same current flows through resistor. • So resistor value should be 3/0.011 = 272.7ohm. We will use 270 ohm.

  41. Calculation on Board

  42. Physical Setup and Demo

  43. Power Calculation

  44. Test Equipment • Multimeter • Oscilloscope • Signal Generator • Power Supply • Logic Analyzer • Hand tools

  45. Multimeter • Use to measure Voltage, Current and Resistance • Some measure frequency, capacitance, temperature and more • *** Caution*** • Take extra care when measuring current • Start with a selection higher than the highest expected value

  46. Making Connections • Voltage is measured across device in circuit • Current is measured in-line in circuit • Resistance is measured across device, outside circuit

  47. Oscilloscope • Provides detailed graphic representation of signals • Essential for signals with ac components • Usefull for monitoring noise

  48. Wire Stripping and Soldering • For connectivity on PCBs • For connectivity with connectors • For connectivity with panel components • For connectivity with general parts

  49. Wire Strippers • Automatic • Manual

  50. Manual Strippers • Use the wire size label on tool or.. • Use a position with a hole slightly larger than the wire diameter

More Related