Electrical Theory and SMAW Welding Flashcards

Vocabulary flashcards covering electrical principles, Ohm's law, welding currents, and SMAW equipment from the lecture notes.

Electricity

The movement of free electrons from one place to another.

Conductor

An object or material that allows the flow of electrical current because its electrons easily leave the atom's nucleus.

Insulator

An object or material that resists or stops the flow of electricity because its atoms do not allow easy electron movement.

Circuit

A closed path along which electrons can flow.

Voltage

The electrical force or pressure that pushes free electrons and causes current flow, measured in volts ($V$).

Current

The flow of electrons past a given point in a circuit per second, measured in amperes ($A$).

Resistance

The opposition to free electron flow that limits or controls current flow in a circuit, measured in ohms ($\Omega$).

Ohm's Law

A mathematical formula used to calculate the relationship between voltage ($E$), current ($I$), and resistance ($R$) in a circuit ($E = I \times R$).

Wattage

A measurement of the amount of electrical energy or power in an arc, calculated by multiplying voltage times amperes ($W = V \times A$).

Temperature

The degree or level of thermal energy in a material, measured in degrees with a thermometer.

Heat

The total quantity of thermal energy in a material, which depends on both its temperature and its weight or mass.

Ion

A negatively or positively charged atom that is conductive.

Shielded Metal Arc Welding (SMAW)

An arc welding process that uses a constant current power source and a flux-covered metal rod to provide a shield to the arc and weld puddle.

Alternating Current (AC)

A type of welding current where the direction of electron flow rapidly reverses, distributing heat evenly between the base metal and the electrode.

Anode

The positive terminal or side of an electric arc.

Cathode

The negative terminal or side of an electric arc.

Rectifier

An electrical device that allows current to flow in one direction only, used to convert alternating current ($\text{AC}$) to direct current ($\text{DC}$).

Direct Current Electrode Negative (DCEN)

A direct current setup where heat from the arc is concentrated on the electrode, resulting in shallow penetration into the base metal.

Direct Current Electrode Positive (DCEP)

A direct current setup where heat from the arc is concentrated on the base metal, promoting deep penetration and creating a more forceful arc.

Inverter

A compact welding power supply that uses solid-state electronics to change incoming power frequency from $60$\,Hz to several thousand hertz.

Open Circuit Voltage (OCV)

The voltage at the electrode before an arc is struck when no current is being drawn, limited to a maximum safe voltage of $80$\,V.

Operating Voltage

The actual voltage across the arc while welding, typically between $17$\,V and $40$\,V.

Arc Blow

The wandering of an electric arc caused by an unbalanced magnetic field around the joint.

Magnetic Flux Lines

Lines of magnetic force that circle around the path of current flow whenever electrons travel through a conductor.

Duty Cycle

The percentage of time in a 10-minute period that a welding machine can be used continuously at its maximum rated current.

Welding Leads

Insulated conductors (also called welding cables) that carry high-amperage current between the power source, electrode holder, and work clamp.

Electrode Holder

A mechanical clamping device connected to the welding cable that holds the electrode rod and conveys current to it.

Work Clamp

A clamping device used to attach the work lead securely to the base metal to complete the electrical circuit.

Step-Down Transformer

A transformer in a welding machine that converts high input voltage and low amperage to lower output voltage and higher welding current.