Chapter 12 Glossary

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AND gate. An electronic gate or switch that has two or more inputs and produces a 1 if any one or more of the inputs is 1. capacitor. A device designed to store an electrical charge. It consists of two metal plates (conductors) separated by an insulator. circuit breaker. A device made of a bimetallic strip that heats up and bends if too much current is flowing through the circuit, stopping current flow. conductivity. A material’s ability to conduct electric current. conductor. A material through which electric current flows easily. diode. A device that allows current to flow in one direction only. Diodes are most commonly used as rectifiers to change alternating current to direct current. electronics. The use of electrically controlled parts to automatically control or change current in a circuit. farad. A unit used to measure the storage potential of a capacitor. fuse. A current-limiting device consisting of a thin filament that melts when too much current reaches it. This stops current flow in the circuit. insulator. A material through which electric current does not flow. integrated circuit. A single electronic component that replaces a whole group of separate components. One integrated circuit may contain the equivalent of about 1,000,000 separate components. laser. A form of radiation that has been boosted to a high level of energy and produces a strong, narrow beam of light. “Laser” is an acronym for Light Amplification by Stimulated Emission of Radiation. load. The weight, mass, or force placed on a structure (Ch. 6); in an electrical circuit, any current- using device. logic gates. Electronic switches used to control and modify current in an electronic circuit.

NAND gate. An electronic gate or switch that has two or more inputs. It produces a 1 only if all inputs are 0; produces a 0 if one or more inputs are 1.

NOR gate. An electronic gate or switch that has two or more inputs. It produces a 0 only if all inputs are 1. It produces a 1 if any or all of the inputs are 0.

NOT gate (inverter). An electronic gate or switch with only one input. If the input is 1, it produces a 0. If the input is 0, it produces a 1. ohm. The unit of measurement for electrical resistance.

Ohm’s law. The law of electricity stating that voltage equals the current times the resistance.

Copyright Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only. OR gate. An electronic gate or switch that has two or more inputs. It produces a 1 if any one or more of the inputs is 1. overload. A condition that occurs when devices on an electrical circuit demand more current than the circuit can safely carry; a cause for a fuse or circuit breaker to interrupt current flow. parallel circuit. A circuit that provides more than one path for electron flow. potentiometer. A type of variable resistor that raises and lowers voltage in a circuit. rectifier.An electronic component that converts alternating current to direct current by allowing current flow in only one direction. resistance. Opposition to the flow of electricity. rheostat. A type of variable resistor that raises and lowers electrical current. schematics. Diagrams of electrical or electronic circuits that use symbols to show the location of circuit components. semiconductor. Material that allows electron flow only under certain conditions. Semiconductors have some characteristics of conductors and some characteristics of insulators. series circuit. A circuit that provides only one path for electron flow. series-parallel circuit. A circuit in which some loads are wired in series and others are wired in parallel. superconductor. A quality of a material that allows current flow without resistance at low temperatures. switch. A device that allows a circuit to be turned on and off. transistor. An electronic device with three terminals: a base, emitter, and collector. Voltage applied to the base allows transistors to act as electronic switches. volt. A unit of measurement for electrical pressure. voltage. A measure of electrical pressure. watt. A unit of measurement of the work performed by an electric current.

Watt’s law. The law of electricity stating that power equals voltage times current or current squared times the resistance.