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

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)

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

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)

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.

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

Types of conductors (pg. 54)

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

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

Special Pathways Breadboards Printed Circuit Boards (PCB) Chasis

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)

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

Circuit Protection Devices Fuses In line Panel Circuit Breakers

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

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

Lighting Discharge Lamps Florescent lamp

Lighting Discharge lamps Mercury Vapor

Lighting Discharge lamps Neon lamp Glow lamp Strobe lamp

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 = 12.57 lumens (1’ from center)

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

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

Resistors Adjustable (wire wound) resistor Variable Potentiometer

Resistors Thermisters – changes resistance values as temperature changes.

Resistor Color Code

Tools