Digital Electronics Unit 1.2

Breadboard

A circuit board for wiring temporary circuits, usually used for prototypes or laboratory work

Insulator

A material that does not allow current to flow when voltage is applied because of its high resistance

Current

A movement of electrical charges around a closed path or circuit

Digital Multi-Meter

A piece of test equipment used to measure voltage, current, and resistance in an electronic circuit

Oscilloscope

A piece of test equipment used to view and measure a variety of different waveforms

Digital Waveform

A series of logic 1s and 0s plotted as a function of time

Digital

A way of representing a physical quantity by a series of binary numbers. Can only be specific discrete values

Analog

A way of representing some physical quantity, such as temperature or velocity, by a proportional continuous voltage or current. Can have any value in a defined range.

Square Wave

An almost instantaneous rise and decay of voltage or current in a periodic pattern with time and with a constant peak value

Conductor

Any material that allows the free movement of electric charges, such as electrons, to provide an electric current

Electron

Basic particle of negative charge in orbit around the nucleus in an atom

Electron Flow

Current of negative charge in motion. Direction is from the negative terminal of the voltage source to the positive side. Opposite to the conventional current

Clock

Digital signal in the form of a rectangular pulse train or a square wave

Duty Cycle

Fraction of the total period that a digital waveform is in the high state. DC = th/T

Sine Wave

One in which amplitude varies in proportion to the sine function of an angle

Series Circuit

One that has only one path for current

Parallel Circuit

One that has two or more branches for separate current from one voltage source

Resistance

Opposition to current. Unit is the ohm

Proton

Particle with a positive charge in the nucleus of an atom

555 timer

TTL- compatible IC that can be wired to operate in several different modes, such as a one-shot and an astable multivibrator

Simulation

Testing design function by specifying a set of inputs and observing the resultant outputs. Generally shown as a series of input and output waveforms

Kirchhoff's Current Law

The algebraic sum of all currents in a series curcuit equal the total current supplied by the source

Kirchhoff's Voltage Law

The algebraic sum of all voltages in a parallel circuit equal the total voltage supplied by the source

Period

The amount of time required for one complete cycle of a periodic event or waveform

Conventional Current

The direction of current flow associated with positive charge in motion. The current flow direction is from a positive to negative potential, which is in the opposite direction of electron flow

Logic High

The higher of two voltages in a digital system with two logic levels

Amplitude

The instantaneous voltage of a waveform

Logic Low

The lower of two voltages in a digital system with two logic levels

Nucleus

The massive, stable part of the atom that contains both protons and neutrons

Frequency

The number of cycles per unit time of a periodic waveform

Falling Edge

The part of a pulse where the logic level is in transition from a high to a low

Atom

The smallest particle of an element

Hertz

Unit of frequency. Equals one cycle per second

Ohms

Unit of resistance

Ohm's Law

V=IR