1. Circuits and electricity basics interactive materials spring 2016 Stacey Kuznetsov kstace@asu.edu

2. what is design? imagining the future

3. tangible interaction systems that are physically embodied in the real world computationally-mediated interfaces between people, things, and environments

4. electrical circuits created using flexible conductive materials (such as conductive threads, paints, and fabrics) in conjunction with discrete electronics components (such as lights, batteries, switches, and sensors). http://alumni.media.mit.edu/~emme/guide.pdf soft circuits

5. LED batter y copper tape

6. our first circuit copper tape direction of electricity flow through the circuit

7. electricity “flow of electric charge”

8. on the atomic level

9. charge

10. electrostatic force

11. atomic number

12. charge carriers

13. flow of charge

14. Energy (electric potential difference) One volt is defined as the difference in electric potential between two points of a conducting wire when an electric current of one ampere dissipates one watt of power between those points.

15. Disassembled CR2032 battery From left — negative cup from inner side with layer of lithium (oxidized in air), separator (porous material), cathode (manganese dioxide), metal grid — current collector, metal casing (+) (damaged while opening the cell), on the bottom is plastic insulation ring

16. Voltage Voltage is the difference in charge between two points Measured in Volts (V)

17. current How fast charge is flowing at any given point Measured in Amperes (I) Amps = Coulombs per second

18. conductivity How well a material supports the flow of electricity Conductors have more loosely-bound, mobile electrons

19. resistance How well a material opposes the flow of electricity Insulators have tightly bound electrons Measured in ohms (Ω)

20. water analogy voltage current how fast water is moving stored energy resistance “narrowness” of a pipe how much the material opposes the current

21. V = I * R V = Voltage in volts I = Current in amps R = Resistance in ohms What is the current across a circuit with a voltage of 1V and resistance of 1 ohm? Ohm’s law 1V =1A * 1R What happens to the current when resistance=2 ohms and voltage = 1V? 1V =0.5A * 2R

22. V = I * R Ohm’s law 1V =0.5A * 2R

23. A closed loop through which electricity can travel A path or “route” for electrons to follow what is a circuit?

24. seriesparallel

25. Electricity always favors the path of least resistance to ground short circuit http://courses.ischool.berkeley.edu/i290- 4/f08/slides/Thursday_Week2_Intro_Physical_Computing.pdf

26. short circuit

27. LED acts as a “resistor” copper tape direction of electricity flow through the circuit

28. multimeter a device that can measure current, voltage, resistance, and electrical continuity diagnose problems in your circuit

29. continuity Is there a connection between 2 points?

30. resistance measure resistance of copper tape Set the approximate range and slightly higher than the component’s resistance

31. voltage Measure the voltage drop across different parts of your circuit Set to DC Volts Choose a range that is closest to but greater than your expected voltage

32. current Connect the voltmeter in series with your circuit

33. calculate the total resistance in your circuit V = IR Measure the voltage and current with the multimeter

34. switch

35. 1 minute brainstorm 5 everyday materials that are conductive

36. 1 minute brainstorm 5 everyday objects that can act as a switch

37. switch examples

38. Due next Wednesday Creative switch Use a battery, LED, and any conductive material (thread, copper tape, paint, etc.) Your switch can be any common object (safety pin, carabiner, etc.) BE CREATIVE! Using a voltmeter, measure the resistance across your circuit. Use ohm’s law to compute the current

39. Due next Wednesday Upload a video of your switch and ohm’s law calculation to the class blog Reading and presentation due Wednesday

40. switch examples