FM transmitter

An FM transmitter is a portable device that plugs into the headphone jack or proprietary output port of a portable audio or video device, such as a portable media player, CD player, or satellite radio system. The sound is then broadcast through the transmitter, and plays through an FM broadcast band frequency. Purposes for an FM transmitter include playing music from a device through a car stereo, or any radio.

The FM-transmitter plugs into the audio output of audio devices and converts the audio output into an FM radio signal, which can then be picked up by appliances such as car or portable radios. Most devices on the market typically have a short range of up to 30 feet (9 meters) with any average radio (up to about 75 feet (23 meters) with a very good radio under perfect conditions) and can broadcast on any FM frequency from 76.0 to 108.0 MHz (or 88.1 to 107.9 in the US). Some lower-cost transmitters are hard-wired to the 87.7–91.9 MHz band allocated to educational broadcasts in the United States, or a certain other smaller range of frequencies.

FM transmitters are usually battery driven, but some use the cigarette lighter socket in cars, or draw their power from the device itself. They are typically used with portable audio devices such as CD or MP3 players, but are also used to broadcast other outputs (such as that from a computer sound card) throughout a home or other building.

Blu-ray Disc

Blu-ray Disc (official abbreviation BD) is an optical disc storage medium designed to supersede the standard DVD format. Its main uses are for storing high-definition video, PlayStation 3 video games, and other data, with up to 25 GB per single-layered, and 50 GB per dual-layered disc. Although these numbers represent the standard storage for Blu-ray Disc drives, the specification is open-ended, with the upper theoretical storage limit left unclear. The discs have the same physical dimensions as standard DVDs and CDs.

The name Blu-ray Disc derives from the "blue laser" used to read the disc. While a standard DVD uses a 650 nanometer red laser, Blu-ray Disc uses a shorter wavelength 405 nm laser, and allows for almost ten times more data storage than a DVD. The laser color is called "blue," but is violet to the eye, and is very close to ultraviolet ("blacklight").

During the high definition optical disc format war, Blu-ray Disc competed with the HD DVD format. Toshiba, the main company that supported HD DVD, conceded in February 2008, and the format war came to an end.^[2] In late 2009, Toshiba released its own Blu-ray Disc player.^[3]

Blu-ray Disc was developed by the Blu-ray Disc Association, a group representing makers of consumer electronics, computer hardware, and motion pictures. As of June 2009, more than 1,500 Blu-ray Disc titles were available in Australia and the United Kingdom, with 2,500 in Japan, the United States and Canada.^[4][5]

Blu-Ray Discs can be clustered together in systems such as optical jukeboxes to increase data storage. This increase of storage can span multiple terabytes and utilize hundreds of Blu-Ray Discs. These systems are currently the largest storage units using Blu-Ray technology.