| • Science | • People | • Locations | • Timeline |
Household electrical wiring is used to send an address and a command via a digital signal on 120 kHz, during the quiet zero crossings of the 50 or 60 Hz AC alternating current waveform. More advanced versions can also query devices to respond with their status, such as "off" or "on" – or even with the temperature or another sensor reading. Devices usually plug into the wall, where a lamp, televisionSee TV (disambiguation) for other uses and Television (band) for the rock band Television is a telecommunication system for broadcasting and receiving moving pictures and sound over a distance. The term has come to refer to all the aspects of television p, or other household appliance plugs in; however some built-in controllers are also available for wall switches and ceiling fixtures.
The relatively high- frequencyFrequency is the measurement of the number of times that a repeated event occurs per unit time. To calculate the frequency, one fixes a time interval, counts the number of occurrences of the event within that interval, and then divides this count by the l signal cannot pass through a transformerThe word Transformer can also mean: The Transformers toys, and the related comics and animated television series which have run from the 1980s onwards. A glam rock album by Lou Reed, named Transformer . Transformers ''Typical electrical configurations See or across phasePhase from the Greek phasis meaning 'appearance', has a number of related meanings in English. The phase of a waveform is the position of any peak or trough compared to the same feature on a second waveform. A phase of matter is a physically distinctive fs of power, so a repeaterIn telecommunication, the term repeater has the following meanings: #An analog device that amplifies an input signal regardless of its nature (analog or digital). A digital device that amplifies, reshapes, retimes, or performs a combination of any of thes is sometimes used with a system. In order to block signals from getting in or out, an attenuatorAn attenuator is a telecommunication device that reduces the amplitude of a signal without appreciably distorting its waveform. Attenuators are usually passive devices, and can either be. The degree of attenuation may be fixed, continuously adjustable, or may also be used.