Neets Master Glossary

1-17 DEFLECTION PLATES—Two pairs of parallel electrodes, one pair set forward of the other and at right angles to each other, parallel to the axis of the electron stream within an electrostatic cathode-ray tube [6]. DEGENERATION—The process whereby a part of the output signal of an amplifying device is returned to its input circuit in such a manner that it tends to cancel part of the input [7]. DEGENERATIVE FEEDBACK—Feedback in which the feedback signal is out of phase with the input signal; also called NEGATIVE FEEDBACK [8]. DEGREE-OF-FREEDOM—The number of axes about which a gyro is free to precess [15]. DEIONIZATION POTENTIAL—The potential at which ionization of the gas within a gas-filled tube ceases and conduction stops; also referred to as extinction potential [6]. DEIONIZATION TIME—In a spark gap, the time required for ionized gas to return to its neutral state after the spark is removed [18]. DELTA—A three-phase connection in which windings are connected end-to-end, forming a closed loop that resembles the Greek letter delta. A separate phase wire is then connected to each of the three junctions [5]. DEMODULATION—The removal of intelligence from a transmission medium [12]. DEMODULATOR—A circuit used in servosystems to convert an ac signal to a dc signal. The magnitude of the dc output is determined by the magnitude of the ac input signal, and its polarity is determined by whether the ac input signal is in or out of phase with the ac reference voltage [15]. DeMORGAN'S THEOREM—A theorem which states that the inversion of a series of AND applications is equal to the same series of inverted OR applications, or the inversion of a series of OR applications is equal to the same series of inverted AND applications. In symbols, DENSITY—(1) The compactness of a substance. (2) Mass per unit volume [10]. DEPLETION REGION—The region in a semiconductor where essentially all free electrons and holes have been swept out by the electrostatic field which exists there [7]. DEPOT-LEVEL MAINTENANCE (SM&R CODE D)—Supports SM&R Code I and SM&R Code O activities through extensive shop facilities and equipment and highly skilled personnel [14]. DESIGNATION—Operational phase of a fire-control or track radar during which the radar is directed to the general direction of a desired target [18]. DETECTION—The separation of low-frequency (audio) intelligence from the high-frequency carrier [17]. DETECTOR—A mixer or converter in a superheterodyne receiver [18]. DICE—Uncased chips [14].