All circuits are analog circuits.
The components of analog circuits are given below.
- resistor (抵抗器)
A resistor is used to limit the flow of current.
Capacitors can store electrons.
When current flows through a coil, a magnetic field is created.
- transformer (トランス、変圧器)
A transformer is composed of two coils positioned so that their
magnetic fields interact.
- power supply (電源)
In order for a circuit to operate, a power supply must be connected.
- voltage source (電圧源)
A voltage source outputs a constant voltage.
- current source (電流源)
A current source outputs a constant current.
- battery (電池)
A battery is a kind of portable voltage source.
- ground (接地、グラウンド)
Ground is the zero reference point in a circuit.
Analog circuits have many characteristics.
- resistance (レジスタンス、抵抗)
Resistance is a measure of how difficult it is for current to flow
through a resistor.
- capacitance (キャパシタンス、静電容量)
The amount of charge that a capacitor can store is measured by its capacitance.
- inductance (インダクタンス)
The inductance of a coil is related to its ability to generate magnetic flux.
- impedance (インピーダンス)
Impedance is similar to resistance, but applies to capacitors and inductors
- current (電流)
The movement of electrons in a circuit creates current.
- DC: direct current (直流)
Current that is constant is called DC.
- AC: alternating current (交流)
Current that is changes periodically is called AC.
- phase (位相)
The relative value of an AC waveform can be represented by its phase.
- frequency (周波数)
Frequency is the rate of change of an AC waveform.
- amplitude (振幅)
An AC waveform's amplitude is its maximum value.
- voltage (電圧)
The voltage drop across a resistor is proportional to its resistance.
- peak-to-peak (ピーク間、ピーク−ピーク)
The peak-to-peak voltage of an AC waveform is the voltage difference between
the minimum and maximum values of the waveform.
The RMS voltage of an AC waveform is the value obtained by taking the
square-root of the average of the square of the waveform.
- series (直列接続)
The total resistance of two resistors connected in series is the sum
of the individual resistances.
- parallel (並列接続)
The total capacitance of two capacitors connected in parallel is the sum
of the individual capacitances.
- gain (利得、増幅度)
Gain is the ratio of the output voltage to the input voltage in an amplifier
Digital circuits are special types of analog circuits.
The components of a digital circuits are as follows.
- input (入力)
Digital circuits can have one or more inputs.
- output (出力)
A digital circuit processes its inputs to produce one or more outputs.
- NOT gate
A NOT gate inverts its input.
- AND gate
The output of an AND gate is true only if all inputs are true.
- NAND gate
A NAND gate is an AND gate whose output has been inverted.
- OR gate
The output of an OR gate is true if at least one of the inputs is true.
- NOR gate
If the output of an OR gate is inverted, a NOR gate results.
- XOR (exclusive OR) gate
An XOR gate is similar to an OR gate, but an XOR gate's output is true
only if only one of its inputs is true.
- RS flip-flop
The most basic type of memory circuit if an RS flip-flop.
- JK flip-flop
A JK flip-flop is a more complicated memory circuit.
- transistor (トランジスタ)
Digital circuits are made mainly of transistors.
Digital circuits have characteristics such as those listed below.
- truth table (真理値表)
The relationship between inputs and outputs is shown in a truth table.
- logic levels: high, low (論理レベル)
The inputs and outputs of most digital circuits use two logic levels
referred to as high and low.
- timing chart (タイミングチャート)
The change in logic values as a function of time is called a timing chart.
- propagation delay (伝搬遅延、伝達遅れ時間)
When the input to a digital circuit changes, its output does not change
immediately. This time lag is called propagation delay.
The number of inputs to a digital circuit is its fan-in.
The number of inputs that an output of a digital circuit can drive
is the output's fan-out.
- TTL(transistor-transistor logic)
One way of making digital circuits is called TTL.
(complementary metal oxide semiconductor) (相補型金属酸化膜半導体)
The most common way of making digital circuits today is called CMOS.
Processors are the core of a computer.
Data is stored in some type of storage device.
You can build your own PC using the following parts.
- mother board (マザーボード)
The mother board is the main part of a PC.
The CPU is inserted into a slot on the mother board.
- memory (メモリ)
The main memory of a PC uses DRAMs.
- case (ケース)
All the components of a PC are placed in a case.
- hard disk (ハードディスク)
The operating system and other files are stored on a hard disk.
- CDROM drive
To install software, a CDROM drive is usually necessary.
- video card (ビデオ・カード)
The video card is necessary to display output from your PC.
- monitor (モニタ)
The video card is connected to a monitor.
- cables (ケーブル)
Many cables are necessary to connect various parts of your PC.
- keyboard (キーボード)
You can input text to your PC using a keyboard.
- mouse (マウス)
A mouse is needed to use graphical user interfaces.
© 2003 David Asano. All Rights Reserved