Friday, 29 March 2024, 4:15 PM
Site: edulabs.org academy
Course: Activity Examples (Activity Examples)
Glossary: Electronics (Mike Jaroch)
B
BACK RESISTANCEThe larger resistance value observed when you are checking the resistance of a semiconductor [16]. |
BALANCED MIXERA waveguide arrangement that resembles a T and uses crystals for coupling the output to a balanced transformer [18]. |
BALANCED PHASE DETECTORA circuit that controls the oscillator frequency (afc) [17]. |
BAND-REJECT FILTERA tuned circuit that does not pass a specified band of frequencies [9] [16]. |
BANDPASS FILTERA filter that allows a narrow band of frequencies to pass through the circuit. Rejects or attenuates frequencies that are either higher or lower than the desired band of frequencies [9] [16]. |
BANDWIDTHThe difference between the highest usable frequency of a device (upper frequency limit) and the lowest usable frequency of the device (lower frequency limit) - measured at the half-power points [8] [9] [12] [15]. |
BARRETTERA type of bolometer characterized by an increase in resistance as the dissipated power rises [16]. |
BASE The element in a transistor that controls the flow of current carriers [7]. (1) A reference value. (2) A number that is multiplied by itself as many times as indicated by an exponent. (3) Same as radix. (4) The region between the emitter and collector of a transistor that receives minority carriers injected from the emitter. It is the element that corresponds to the control grid of an electron tube [13]. |
BASE-INJECTION MODULATORSimilar to a control-grid modulator. The gain of a transistor is varied by changing the bias on its base [12]. |
BATTERYA device for converting chemical energy into electrical energy [1]. |
BATTERY CAPACITYThe amount of energy available from a battery. Battery capacity is expressed in ampere-hours [1]. |
BAUDA measurement of speed based on the number of code elements or units per second [17]. |
BAYPart of an antenna array [10]. |
BEAMSee LOBE [18]. |
BEAM-LEAD CHIPSemiconductor chip with electrodes (leads) extended beyond the wafer [14]. |
BEAM-POWER TUBEAn electron tube in which the grids are aligned with the control grid. Special beam-forming plates are used to concentrate the electron stream into a beam. Because of this action, the beam-power tube has high power-handling capabilities [6]. |
BEARINGAn angular measurement of the direction of an object from a reference direction, such as true north [11]. |
BEARING RESOLUTIONAbility of a radar to distinguish between targets that are close together in bearing [18]. |
BEAT FREQUENCIESDifference and sum frequencies, which result from the combination of two separate frequencies [18]. |
BEAT FREQUENCYThe difference between the oscillator frequency and the unknown audio frequency [16]. |
BEAT-FREQUENCY OSCILLATORAn additional oscillator used in a receiver when it is receiving a cw signal. It provides an audible tone [17]. |
BELThe unit that expresses the logarithmic ratio between the input and output of any given component, circuit, or system [16]. |
BETAThe ratio of a change in collector current to a corresponding change in base current when the collector voltage is constant in a common-emitter circuit [7]. |
BEVERAGE ANTENNAA horizontal, long-wire antenna designed for reception and transmission of low-frequency, vertically polarized ground waves [10]. |
BIASDifference of potential applied to a vacuum tube or transistor to establish a reference operating level [13]. |
BIAS CURRENTCurrent that flows through the base-emitter junction of a transistor and is adjusted to set the operating point of the transistor [13]. |
BIDIRECTIONAL ARRAYAn array that radiates in opposite directions along the line of maximum radiation [10]. |
BINARY(1) A number system that uses a base, or radix, of 2. Two digits (1 and 0) are used in the binary system. (2) Pertaining to a characteristic that involves the selection, choice, or condition in which there are only two possibilities. (3) A bistable multivibrator (flip-flop) is one example of a binary device [13]. |
BINARY CODEA method of representing two possible conditions (on or off, high or low, one or zero, the presence of a signal or absence of a signal). Electronic circuits designed to work in such a way that only two conditions are possible [13]. |
BINARY DIGIT(1) A character that represents one of the two digits in the number system that has a radix of two. (2) Either of the digits 0 or 1 that may be used to represent the binary conditions of on or off [13]. |
BINARY NOTATIONSee BINARY NUMBER SYSTEM [13]. |
BINARY NUMBER SYSTEMA number system using two digits, symbols, or characters (usually 1 and 0) [13]. |
BINARY POINTThe radix point that separates powers of two and fractional powers of two in a binary number [13]. |
BINARY-CODEDThe state in which conditions are expressed by a series of binary digits (0's and 1's) [13]. |
BISTABLEA device that is capable of assuming either one of two stable states [13]. |
BISTABLE MULTIVIBRATORA multivibrator that has two stable states. It remains in one of the states until a trigger is applied. It then flips to the other stable state and remains there until another trigger is applied. Also referred to as a FLIP-FLOP [9] [13]. |
BLACKThe reference color of equipment that passes unclassified information. It normally refers to patch panels [17]. |
BLEEDER CURRENTThe current through a bleeder resistor. In a voltage divider, bleeder current is usually determined by the 10 percent rule of thumb [1]. |
BLEEDER RESISTORA resistor used to draw a fixed current [1]. |
BLIPSee PIP [18]. |
BLOCK DIAGRAMA diagram in which the major components of an equipment or a system are represented by squares, rectangles, or other geometric figures, and the normal order of progression of a signal or current flow is represented by lines [4]. |
BLOCKED-GRID KEYINGA method of keying in which the bias is varied to turn plate current on and off [12]. |
BLOCKINGA condition in an amplifier, caused by overdriving one or more stages, in which the amplifier is insensitive to small signals immediately after reception of a large signal [18]. |
BOLOMETERA loading device that undergoes changes in resistance as changes in dissipated power occur [16]. |
BONDING WIRESFine wires connecting the bonding pads of the chip to the external leads of the package [14]. |
BOOLEAN(1) Pertaining to the process used in the algebra formulated by George Boole. (2) Pertaining to the operations of formal logic [13]. |
BOOLEAN ALGEBRAA system of logic dealing with on-off circuit elements associated by such operators as the AND, OR, NAND, NOR, and NOT functions [13]. |
BOOLEAN LOGICSee BOOLEAN ALGEBRA [13]. |
BOUNDARY CONDITIONSThe two conditions that the E-field and H-field within a waveguide must meet before energy will travel down the waveguide. The E-field must be perpendicular to the walls and the H-field must be in closed loops, parallel to the walls, and perpendicular to the E-field [11]. |
BRANCHAn individual current path in a parallel circuit [1] [4]. |
BREAKIn a switch, the number of breaks refers to the number of points at which the switch opens the circuit; for example, single break and double break [3]. |
BREAKDOWNThe phenomenon occurring in a reverse-biased semiconductor diode. The start of the phenomenon is observed as a transition from a high dynamic resistance to one of substantially lower dynamic resistance. This is done to boost the reverse current [7]. |
BRIGHTNESS CONTROLThe name given to the potentiometer used to vary the potential applied to the control grid of a CRT [6]. |
BROADSIDE ARRAYAn array in which the direction of maximum radiation is perpendicular to the plane containing the elements [10] [18]. |
BRUSHESSliding contacts, usually carbon, that make electrical connection to the rotating part of a motor or generator [5]. |
BUFFERA voltage amplifier used between the oscillator and power amplifier [12]. |
BUFFER AMPLIFIERAn amplifier that isolates one circuit from another. It decreases the loading effect on an oscillator by reducing the interaction between the load and the oscillator [9] [18]. |
BUILT-IN TEST EQUIPMENT (BITE)A permanently mounted device that is used expressly for testing an equipment or system [14]. |
BUNCHER CAVITYThe input resonant cavity in a conventional klystron oscillator [11]. |
BUNCHER GRIDIn a velocity-modulated tube, the grid that concentrates the electrons in the electron beam into bunches [11]. |
BURNISHING TOOLA tool used to clean and polish contacts on a relay [3]. |
BUS BARA heavy copper strap or bar used to connect several circuits together when a large current-carrying capacity is required [4]. |
BYPASS CAPACITORA capacitor used to transfer unwanted signals out of a circuit; for example, coupling an unwanted signal to ground. Also called a DECOUPLING CAPACITOR [8]. |