Terminology/Definitions

This page is a constant work in progress as the hobby is constantly changing.

Contents: A * B * C * D * E * F * G * H * I * J * K * L * M * N * O * P * Q * R * S * T * U * V * W * X * Y * Z

A

AC — alternating current. An electrical current that reverses directions at regular intervals. Wall power, or mains, is AC and in North America, it cycles 60 times per second, while in England and Australia, it cycles 50 times per second.

Arduino. An Open Source system for developing microprocessor-controlled projects, including a reference design for a project board, as well as an integrated development environment (IDE) and linking to the Atmel firmware development chain. Further, a series of printed-circuit boards that can plug into the Arduino board — called “shields” — have been development for the project boards, extending the capabilities of the project environment.

ATmega. A brand of microcontroller developed and sold by Atmel Corp. The Arduino line of project boards uses ATmega microprocessors (the 168, 328p, 1280 and 2560, depending upon the Arduino model). ATMega chips have an entire different firmware development chain than chips from Microchip Technology and therefore can’t share code.

Amps (amperes). A unit of electrical current, an amp is the amount of electricity being drawn through the power system. A product that draws 10 amps uses twice as much electricity as a product that draws five amps. See also Electricity basics.

B

BNC — Bayonet Nut Connection. A type of common radio frequency connector used on coaxial cables. See RG-58.

C

C7, C9 light bulbs. Known as the “traditional” Christmas light, these types of strings had their hey-day in the 1950s and 1960s. Many lighting hobbyists switched to “mini” bulbs in the 1970s. The C7 bulb is about 2-inches tall, while the C9 is about 3-inches tall. The C7 uses the candelabra base, while the C9 uses the intermediate base (both of which are Edison screw-in types). Both sizes come in both clear and opaque colors and both come in 7-watt versions, while the C7 comes in a 2.5-watt version and the C9 in a 3.5-watt version. The maximum number of 2.5-watt lamps per 15-amp circuit is about 575 (or 765 lamps per 20-amp circuit) or 300 lamps per outlet, while the maximum number of 7-watt lamps per 15-amp circuit is about 200 (274 per 20-amp circuit) or about 125 lamps per outlet.

Capacitor. An electrical component that stores an electric charge and releases it when its needed. Typically used in Christmas lighting as a filter in power supply circuits.

Circuit. The path (usually wire) through which current flows between an electrical energy source and an electrical device, appliance or fixture.