Electrical Components

Electronic component

Basic physical part used in a circuit to affect electrons, fields, signals, or electrical energy; used when identifying parts on a circuit board during inspection.

Datasheet

Technical document that lists specifications, ratings, limits, characteristics, and performance details for a part; used before selecting a connector, diode, sensor, or IC.

Discrete component

Individual packaged part that performs one main function rather than being built into a larger integrated package; used when replacing or identifying a single resistor, diode, or capacitor.

Terminal

Electrical connection point where a part connects to wires, boards, or other parts; used when checking where a wire lands on a terminal block.

Lead

Metal wire or contact extending from a part so it can be connected into a circuit; used when soldering a through-hole resistor or capacitor onto a PCB.

Active component

Part that depends on external energy and can control or add signal energy; used when discussing powered devices like transistors, ICs, or amplifiers.

Passive component

Part that stores, dissipates, transfers, or filters energy without adding net signal energy; used when reviewing resistors, capacitors, inductors, and filters.

Electromechanical component

Part that performs an electrical function using movement, mechanical contact, or moving structures; used when testing relays, switches, motors, or solenoids.

Semiconductor

Material-based part whose conductivity can be controlled; used when discussing diodes, transistors, solar cells, and ICs.

Electronic symbol

Standard drawing mark used to represent a part on a circuit diagram; used when reading schematics.

Reference designator

Label on a schematic used to identify a specific part; used when locating R12, C5, J3, or U1 on a PCB.

Transistor

Three-or-more-terminal semiconductor part used to switch or amplify signals and power; used when a small control signal switches a larger load.

FET (Field-Effect Transistor)

Voltage-controlled device used for switching or amplification with very little input current; used when controlling current flow with a voltage signal.

MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor)

Insulated-gate field-effect device used for switching, amplification, logic, and power control; used in efficient load-switching circuits.

Power MOSFET (Power Metal-Oxide-Semiconductor Field-Effect Transistor)

High-current insulated-gate switch; used in power distribution, motor control, or load switching.

BJT (Bipolar Junction Transistor)

Current-controlled semiconductor device using two junctions for amplification or switching; used in small-signal amplifier or switch circuits.

IGBT (Insulated-Gate Bipolar Transistor)

Power switch combining easy gate control with high-current conduction; used in high-power converters, motor drives, or large switching systems.

Diode

Two-terminal semiconductor that usually conducts more easily in one direction; used to prevent reverse current flow.

Rectifier

Part or circuit that converts alternating current into one-direction current; used in AC-to-DC power supplies.

Diode bridge

Four-diode rectifying arrangement that converts AC into full-wave DC; used after an AC source in a power supply.

Schottky diode

Fast diode with low forward voltage drop; used where low voltage loss and fast switching are important.

Zener diode

Reverse-breakdown diode used to hold or reference a set voltage; used for voltage references or overvoltage protection.

TVS diode (Transient Voltage Suppression diode)

Protective diode that absorbs brief high-voltage spikes; used to protect electronics from ESD or voltage transients.

Transient voltage suppression diode

Protective semiconductor that clamps sudden voltage surges; used on external connector lines during cable handling or testing.

LED (Light-Emitting Diode)

Light-emitting semiconductor used for indicators, lighting, and displays; used to show power, fault, or communication status.

Photodiode

Light-sensitive semiconductor that produces current when illuminated; used in optical sensing or light detection.

Thyristor

Latching semiconductor switch that turns on when triggered and remains conducting until current drops; used in controlled power switching.

SCR (Silicon-Controlled Rectifier)

Controlled rectifying switch that conducts after a gate trigger; used where latch-on power control is needed.

Integrated circuit

Many electronic functions fabricated together inside one package; used when a board needs compact logic, processing, regulation, or communication functions.

IC (Integrated Circuit)

Packaged chip containing interconnected miniaturized devices and circuits; used when identifying a voltage regulator, microcontroller, or interface driver.

Mixed-signal integrated circuit

Chip containing both analog and digital functions; used when converting sensor signals into digital data.

Digital electronics

Circuitry based on discrete logic states such as high and low; used in command, telemetry, logic, and control circuits.

Logic gate

Basic digital building block that performs Boolean operations; used when designing simple AND, OR, or NOT control logic.

Microcontroller

Small computer-on-a-chip with processor, memory, and input/output functions; used to control sensors, read inputs, and command outputs.

Analog circuit

Circuit that processes continuously varying signals; used when conditioning sensor signals before digitization.

Programmable logic device

Configurable digital device whose logic behavior can be set after manufacturing; used when custom digital logic is needed without designing a new chip.

FPGA (Field-Programmable Gate Array)

Reconfigurable digital chip made of programmable logic blocks and interconnects; used for high-speed data processing, interface control, or custom spacecraft electronics logic.

CPLD (Complex Programmable Logic Device)

Programmable digital logic chip suited for control and glue-logic functions; used for simpler digital control tasks between larger components.

Battery

Chemical energy source that provides DC electrical energy; used to power a system during backup, testing, or standalone operation.

Power supply

Device or circuit that provides regulated electrical energy to loads; used to provide stable DC voltage to electronics during bench testing.

Solar cell

Light-powered semiconductor device that converts illumination into electrical energy; used on spacecraft solar arrays to generate electrical power.

Photovoltaic cell

Light-to-electricity conversion cell used in panels and arrays; used as the basic power-generating element in a solar panel.

PV array (Photovoltaic array)

Grouped photovoltaic cells or modules connected to produce usable electrical output; used on satellites to generate power from sunlight.

PV panel (Photovoltaic panel)

Flat module of photovoltaic cells used to generate electrical energy from light; used when testing solar power generation.

Photovoltaic device

Light-powered generator that converts illumination into electricity; used in systems that harvest light energy for power.

Electrical generator

Machine that converts mechanical energy into electrical energy; used in ground support equipment or backup power systems.

Generator

Machine that converts motion into electrical energy; used to provide power when grid or facility power is unavailable.

Resistor

Two-terminal part that opposes current flow and follows Ohm’s law; used to limit current, divide voltage, or set bias conditions.

Power resistor

Heat-dissipating current-limiting part designed for higher wattage; used as a dummy load during power supply testing.

Variable resistor

Adjustable resistance element used to change current or voltage; used during testing to vary a circuit condition manually.

Potentiometer

Three-terminal adjustable divider used to set a variable voltage; used to adjust a reference voltage or calibration setting.

Trim pot

Small adjustable divider used for calibration or internal setting; used to fine-tune a circuit during setup.

Thermistor

Temperature-sensitive resistance element with predictable resistance change; used to monitor temperature inside electronics or battery systems.

Photoresistor

Light-sensitive resistance element whose value changes with illumination; used in simple light-detection circuits.

Photo resistor

Light-dependent resistance element; used to detect whether light is present in a basic sensing circuit.

LDR (Light-Dependent Resistor)

Resistance element whose value changes with light intensity; used in automatic brightness or light-level detection circuits.

Varistor

Voltage-dependent protective part that conducts strongly during overvoltage; used to protect a circuit from voltage spikes.

MOV (Metal-Oxide Varistor)

Metal-oxide surge absorber used to clamp excessive voltage; used on power input lines to absorb surge energy.

Capacitor

Two-terminal part that stores and releases electric charge; used to smooth voltage, filter noise, or store temporary energy.

Fixed capacitor

Charge-storage part with a non-adjustable value; used when a known capacitance is needed in a filter or timing circuit.

Ceramic capacitor

Charge-storage part using ceramic dielectric material; used for high-frequency decoupling near IC power pins.

Film capacitor

Charge-storage part using thin plastic film dielectric; used in stable filtering, timing, or power applications.

Electrolytic capacitor

Polarized high-capacitance part using an electrolyte; used for bulk energy storage on power rails.

Aluminum electrolytic capacitor

Polarized high-capacitance part using aluminum oxide dielectric; used in power supplies to smooth DC voltage.

Tantalum electrolytic capacitor

Compact polarized part using tantalum oxide dielectric; used where compact size and stable capacitance are needed.

Polymer capacitor

Low-ESR electrolytic type using conductive polymer; used on low-voltage power rails with fast current changes.

Supercapacitor

Very high-capacitance energy-storage part for backup or burst power; used to keep memory or clocks powered briefly during power loss.

Power capacitor

Large charge-storage part used in power systems or power electronics; used in high-energy power conversion or filtering systems.

Safety capacitor

Line-rated part designed to fail safely in mains-connected circuits; used across or from AC power lines in EMI filters.

Filter capacitor

Charge-storage part used to smooth ripple or remove unwanted frequency components; used to reduce ripple in a DC power supply.

Reservoir capacitor

Large storage part that holds charge to smooth a DC supply; used after a rectifier to maintain voltage between AC peaks.

Bulk capacitor

Large-value storage part that supports power rails during load changes; used near power converters to handle sudden current demand.

Coupling capacitor

Part that passes AC signals while blocking DC between circuit stages; used to pass a signal while isolating different DC bias levels.

Decoupling capacitor

Nearby storage part that stabilizes a supply rail against fast load changes; used near ICs to prevent voltage dips during switching.

Bypass capacitor

Part that shunts noise or AC ripple away from a power line or signal node; used to route high-frequency noise to ground.

Feedthrough capacitor

Noise-filtering part that passes through a shield or enclosure wall; used where a wire enters a shielded electronics box.

Inductor

Magnetic energy-storage part that opposes changes in current; used in DC-DC converters and filtering circuits.

Coil

Wound conductor used to create inductance or magnetic field; used in relays, transformers, inductors, or magnetic sensors.

Choke

Magnetic part used to block high-frequency noise while passing DC or low frequency; used to reduce EMI on power or signal lines.

Transformer

Magnetic device that transfers energy between windings and can change voltage or impedance; used to step voltage up or down or provide isolation.

Ferrite impedance

Magnetic material element used to resist high-frequency noise; used to suppress unwanted high-frequency currents on cables.

Ferrite bead

Small magnetic noise suppressor placed around or in series with a conductor; used on power or signal lines to reduce EMI.

RC network (Resistor-Capacitor network)

Resistor-capacitor arrangement used for timing, filtering, or snubbing; used to create a simple low-pass filter or delay.

RC circuit (Resistor-Capacitor circuit)

Resistor-capacitor circuit with time-dependent charging behavior; used for timing, filtering, debounce, or transient shaping.

Snubber

Protective network used to suppress voltage spikes or switching transients; used across relay contacts or switching devices to reduce spikes.

LC network (Inductor-Capacitor network)

Inductor-capacitor arrangement used for tuning, resonance, or filtering; used in power filters or RF tuning circuits.

LC circuit (Inductor-Capacitor circuit)

Inductor-capacitor circuit that stores energy between magnetic and electric fields; used to select or reject certain frequencies.

Filter

Circuit or part that passes desired frequencies while reducing others; used to remove noise from power, sensor, or communication signals.

RFI filter (Radio-Frequency Interference filter)

Network used to reduce radio-frequency interference; used at power or cable interfaces to keep RF noise from entering or leaving equipment.

Transducer

Device that converts electrical energy to a physical effect or a physical condition to an electrical signal; used when pressure, motion, light, or temperature must become an electrical signal.

Sensor

Device that reacts to environmental conditions by changing electrical behavior or producing a signal; used to measure temperature, current, acceleration, or magnetic field.

Detector

Device used to sense light, heat, motion, radiation, magnetic field, or another physical condition; used to detect whether a signal, object, or condition is present.

Hall-effect sensor

Magnetic-field sensing device that outputs a signal based on field strength; used to detect current, position, or magnetic field without direct contact.

Current sensor

Device that detects electrical flow through a conductor or circuit; used to verify how much current a subsystem is drawing.

LVDT (Linear Variable Differential Transformer)

Magnetic position sensor used to measure linear displacement; used to measure actuator position or mechanical movement.

Rotary encoder

Position sensor that detects shaft angle, direction, or speed; used to track motor shaft position.

Shaft encoder

Rotational sensor that reports angular position or motion; used in mechanisms that need precise angular feedback.

Inclinometer

Angle sensor that measures tilt relative to gravity; used to measure orientation or tilt during ground testing.

Motion sensor

Device that detects movement; used to detect movement of a mechanism or test fixture.

Vibration sensor

Device that detects oscillation, shaking, or mechanical vibration; used during vibration testing of hardware.