1. Introduction to Basic Electrical Circuit Materials
Chapter 3
Introduction to Basic Electrical Circuit Materials

2. Conductors
Pathways that allow electrons to flow through an electrical circuit.
Materials for conductors:
Copper (great conductor and fairly cheap)
Brass (Strong and good conductor)
Aluminum (cheap, light & good conductor)
Silver (awesome conductor, but expensive)

3. Conductance The conductivity of a material is given in siemens (S). 1
Resistance R

4. Conductor Size Cross sectional area
Determines how much current it can handle without overheating.
Circular conductors size – American Wire Gauge System – larger the number, the smaller the cross-sectional area. No. 14 is larger than No. 20 wire.
Circular Mil System (see next slide)

5. Circular Mils The cross sectional area of a conductor.
1 mil = 1/1000th of an inch (0.001”)
Circular mils (cmil) = D2 [diameter squared]
Useful when expressing a conductor size other than r2. Such as rectangular.

6. Insulation
Materials with few free electrons – does not conduct electrons well.
Keeps electrons harnessed.
Rubber
Plastic
Synthetics
Neoprene, Teflon, nylon, polyethylene
Codes – Page 54

7. Types of conductors (pg. 54)

8. Resistance in a Conductor
Four factors that effect the resistance of a conductor.
Cross-Sectional area
Type of material
Length of conductor
Temperature of material
Aluminum
Copper

9. Safety National Electric Code
Guidelines and regulations concerning lengths and gauge of wire as well as safety ratings of materials and conductors.

10. Special Pathways
Breadboards
Printed Circuit Boards (PCB)
Chasis

11. Circuit Devices Switches – Control flow
Actuator – mechanical device that controls the opening and closing of the switch.
SPST – Single-pole (one path); single throw (one circuit)

12. Connectors Ring terminal Insulated ring terminal Flange terminal
Inline splice
Termination Block
Fork terminal
Stranded connector
Wire nut
Split bolt connector

13. Circuit Protection Devices
Fuses
In line
Panel
Circuit Breakers

14. Lighting Incandescent Lamp
Current flowing through a tungsten filament gives off heat and light.

15. Lighting
Halogen Lamp – Tungsten filament is inserted through a glass tube, which is filled with helium.

16. Lighting
Discharge Lamps
Florescent lamp

17. Lighting
Discharge lamps
Mercury Vapor

18. Lighting
Discharge lamps
Neon lamp
Glow lamp
Strobe lamp

19. Measure of light intensity
Candela - amount of light generated by one candle.
Lumen – term used to measure the amount of light generated by lighting systems.
1 candela = lumens (1’ from center)

20. Resistor is a device used to create desirable voltage drops and limit current values in electrical circuits.
Resistors

21. Resistors Carbon composition Thin film Film Chip resistors Wire wound
Metal oxide

22. Resistors
Adjustable (wire wound) resistor
Variable
Potentiometer

23. Resistors
Thermisters – changes resistance values as temperature changes.

24. Resistor Color Code

25. Tools