Basic Electrical Circuit Materials

1. Basic Electrical Circuit Materials Colts Neck High School Applied Technology

2. Conductance • The effectiveness of a conductor is measured in conductance. • The unit of measure for conductance is the siemens. (Ernst von Siemens) G = I/R G = conductance (in siemens) R = is resistance (in ohms)

3. Conductors • Pathways that allow electrons to flow through an electric circuit. • Made from a variety of materials, usually metals. • Copper, Aluminum, Brass, Silver

4. Conductor Size • Circular conductors are sized by the American Wire Gauge System. • The larger the gauge number, the smaller the cross-sectional area • Circular Mils • A mil is equal to 1/1000th of an inch • A circular mil is equal to the diameter of a round conductor squared (D2)

5. Conductor Insulation • Insulators – materials with few free electrons, thus poor conductors of electrons. • Insulation – protective coating surrounding a conductor that prevents contact with other conductors and people.

6. Types of Conductors

7. Conductor Resistance • Cross-sectional area of a conductor • The larger the surface area or diameter of a conductor, the lower the resistance. • Type of material • Different materials have different resistance values. • Length of conductor • The longer the conductor, the greater the resistance. • Temperature of material • Resistance of a material rises with the rising temperature.

8. Special Conductor Pathways • Breadboards – a device consisting of a piece of insulation material with a series of holes aligned in rows across it. Copper strips are run in parallel under it to provide pathways.

9. Special Conductor Pathways • Printed Circuit Board ( PCB) – A thin layer of conductor material, usually copper, cut into strips and attached to an insulated board.

10. Special Conductor Pathways • Chassis – a metallic surface that serves as a part of the circuitry. • Example – the chassis of an automobile.

11. Common Circuit Devices • Common circuit devices provide for a means of controlling the flow of electrons in an electronic or electric circuit. They also provide for safe operation. These include: • Switches • Connectors • Circuit Protection Devices

12. Switches • Switches are categorized by their mechanical actuators, the part that causes it to open or close. • Simplest switch is a single-pole single-throw (SPST)

13. Circuit Protection Devices • Circuit protection devices include fuses and circuit breakers • Fuses are small glass tubes that contain wires that are engineered to burn if the current is too high. • Circuit Breakers are reusable safety devices that work on bi-metal actuators, or magnetism.

14. Connectors • Connectors are used to connect various components and conductors in an electronic or electric circuit. Many of them are solder less, some may require an additional crimping tool.

15. Resistors • Resistor – a component used to create desirable voltage drops and limit current values in electronic circuitry. • Various types exit such as composition resistor, chip resistor , potentiometers, and thermisters

16. Resistor Color Code • Resistors have color coded bands that represent the value, in Ohms, of the resister.