Electronic Engineering Dictionary

Circuit. The complete path of an electric current. A group of electrical components connected together to perform some function. An electronic closed-loop path among two or more points used for signal transfer. A conductor or system of conductors through which an electric current is intended to flow.

Circuit Breaker.
Circuit Breaker	A device designed to open and close a circuit by non-automatic means and to open the circuit automatically on a predetermined over-current without injury to itself when properly applied within its rating. An over-current protection device that automatically shuts off the current in a circuit if an overload occurs. Manufacturers of Circuit Breakers.

Circular DIN. A type of round connector. Definition or examples of Circular DIN Connectors.

Circular MIL. An area equal to that of a circle with a diameter of 0.001 inch. It is used for measuring the cross-sectional area of wires.

Circular MIL-Foot. A unit of volume of a conductor having a cross-sectional area of 1 circular mil and a length of 1 foot.

Circulating Fan. A non-positive displacement mechanical device having an axial fan impeller with or without a protective enclosure. It is designed to circulate air under free-airflow conditions, and may be equipped with a baffle(s) to deflect the air radially. A circulating fan may be suspended from the ceiling, attached to the wall, or stand on a horizontal surface.

Circulator. A passive junction of three or more ports in which the ports can be accessed in such an order that when power is fed into any port it is transferred to the next port, the first port being counted as following the last in order. Companies making RF Circulator Components.

Cladding. The dielectric material surrounding the core of an optical fiber. A low refractive material that surrounds the core of the optic fiber and protects against scattering. Fiber cladding might be glass or plastic.

Clamper. A circuit in which either the upper or lower extremity of a waveform is fixed at a desired value.

Clamping Diode. A diode used to limit the peak voltage on a line to a pre-determined maximum voltage. Also sometimes called a spike killer. Many devices are produced with internal clamping diodes to limit voltage spikes.

Clam Shell. A hinged style of connector backshell, strain relief or safety shield. This particular plastic clam shell strain relief is being used with the Molex style of power connector. Metal clam shells are also possible. Other styles of Connector Back-Shells, with graphics.

Clapp Oscillator. A style of Colpitts oscillator that uses a series resonant tank-circuit.

Class A Amplifier Operation. The type of operation in which the amplifier is biased so that variations in input signal polarities occur within the limits of cutoff and saturation. An amplifier operated in the linear region so the output is not clipped or cut-off. A linear amplifier that uses 100 percent of the input signal, with current flowing 100 percent of the time. The class A amp produces an output that is an amplified version of the input signal and has a 360 degrees [in-phase] relationship with the input signal. A Class A amplifier may output a distorted signal if a large amplitude signal pushes the transistor into the non-linear region of its characteristics.

Class AB Amplifier Operation. The type of operation in which the amplifier is biased so that collector current is cut off for a portion of the alternation of the input signal. An amplifier that operates as a Class A amplifier with low input levers, but operates as a class B amplifier at high drive levels.

Class AB Amplifier

A class AB amplifier clips the output at higher inputs levels, distorting the signal. An amplifier that operates for more than half, but the less than the entire input signal.

Class B Amplifier Operation. The type of operation in which the amplifier is biased so that collector current is cut off for one-half of the input signal. The class B amplifier operates for 50 percent of the time. An amplifier that uses two distinct amplifiers, with one operating during one phase of the signal while the other is forced into cut-off.

Class B Amplifier

During the next phase the amplifier that was operating is forced to cut-off while the previously cut-off amplifier starts to conduct. The two amplifiers working in anti-phase, as in a Push-Pull configuration [with graphic]. An amplifier that is cut off at zero volts on the input signal.

Class C Amplifier Operation. The type of operation in which the amplifier is biased so that collector current is cut off for more than one-half of the input signal, conducting for less than 50 percent of the time. A non-linear amplifier setup which produces a lot of distortion.

Class C Amplifier

Clipper. A circuit or device that limits the instantaneous output signal amplitude to a predetermined maximum value, regardless of the amplitude of the input signal.

Clipper Diode. [line clipper or shunt diode]. A diode in series with a resistor placed in parallel with an incoming signal to clip or limit the amplitude of the signal.

Clipping. The limiting of instantaneous signal amplitudes to a predetermined maximum value.

Clock. A device that generates periodic, accurately spaced signals used for timing applications. Related; Manufacturers of Integrated Circuit Timers, Manufacturers of Integrated Circuit Real Time Clocks. A reference source of timing information. A device providing signals used in a transmission system to control the timing of certain functions such as the duration of signal elements or the sampling rate. A signal waveform used to synchronize digital circuits.

Clock Buffer. A low skew IC used to drive the same clock over different circuit paths. Example 1-Line to 10-Line Clock Buffer IC, in a different section of the site. Normally used to does the same clock signal over multiple lines, with each having nearly identical switching times [low skew], so the the clock arrives at each circuit at nearly the same time.

Clock Driver. A device or circuit used to drive a clock signal. In the case of a single driver contained within a package, the driver is assumed to have a small propagation delay, and precise propagation delay [although not fix]. A clock driver could be the same function as a clock buffer.

Clock Error. The difference between local clock time or value and a designated reference clock time or value.

Clock Generator. A circuit or IC used to generate a clock signal, which would than be used by some other circuit or IC as a clock. An example clock generator is shown in the right side-bar, using a crystal [XTAL] to generate two different clock phases. An oscillator.

Clock Phase Slew. The rate of relative phase change between a given clock signal and a stable reference signal. Refer to Skew for a diagram.

Clock Rate. The rate at which a clock issues timing pulses. The speed or frequency that a processor operates at.

Clock, Real Time. See Real time clock.

Closed-Loop Gain. The voltage gain of an amplifier which uses feedback.

Closed-Loop Voltage Gain. See Closed-Loop Gain.