the input and feed-back signals must be equal
21Dipole antenna — A schematic of a half wave dipole antenna connected to an unbalanced coaxial cable. Better practice is to connect the balanced dipole to the unbalanced line with a balun. A dipole antenna is a radio antenna that can be made of a simple wire, with …
22Electric motor — For other kinds of motors, see motor (disambiguation). For a railroad electric engine, see electric locomotive. Various electric motors. A 9 volt PP3 transistor battery is in the center foreground for size comparison. An electric motor converts… …
23Crystal radio — Crystal set redirects here. For the Australian rock band, see The Crystal Set. A modern reproduction of an antique crystal set. It is tuned to different stations by moving the sliding contact (right) up and down the tuning coil (red). The device… …
24Light-emitting diode — LED redirects here. For other uses, see LED (disambiguation). Light emitting diode Red, pure green and blue LEDs of the 5mm diffused type Type Passive, optoelectronic Working principle Electr …
25Scrambler — For other uses, see Scrambler (disambiguation). In telecommunications, a scrambler is a device that transposes or inverts signals or otherwise encodes a message at the transmitter to make the message unintelligible at a receiver not equipped with …
26Electronic tuner — Pocket sized Korg chromatic LCD tuner, with simulated analog indicator needle The term electronic tuner can refer to a number of different things, depending which discipline you wish to study. In the Discipline of radio frequency electronics an… …
27sensory reception, human — Introduction means by which humans react to changes in external and internal environments. Ancient philosophers called the human senses “the windows of the soul,” and Aristotle described at least five senses sight, hearing, smell, taste, and… …
28Nigeria — Nigerian, adj., n. /nuy jear ee euh/, n. a republic in W Africa: member of the Commonwealth of Nations; formerly a British colony and protectorate. 107,129,469; 356,669 sq. mi. (923,773 sq. km). Cap.: Abuja. Official name, Federal Republic of… …
29Secure Digital — SDHC redirects here. For the gene, see SDHC (gene). SD, SDHC, SDXC SD (top), miniSD, microSD cards Media type Memory card Capacity SDSC (SD): 1 MB to 2 GB although 4 GB cards are available SDHC: 4 GB to 3 …
30Deinterlacing — is the process of converting interlaced video, such as common analog television signals or 1080i format HDTV signals, into a non interlaced form. Interlaced video frame consists of two sub fields taken in sequence, each sequentially scanned at… …
