Inductors Flashcards
What do inductors do?
Inductors store energy in a magnetic field when current flows through them and oppose changes in current.
How do inductors work?
When current flows through a coil of wire, it generates a magnetic field; any change in current induces a voltage opposing the change.
What are the main types of inductors?
Air-core, iron-core, ferrite-core, toroidal, and variable inductors.
What is an air-core inductor?
An inductor without a magnetic core, used in high-frequency applications.
What is a ferrite-core inductor?
An inductor with a core made of ferrite material, used to increase inductance and reduce losses.
What is a toroidal inductor?
An inductor wound on a doughnut-shaped core, offering high efficiency and low electromagnetic interference (EMI).
What is the inductance of an inductor measured in?
Henries (H), typically in microhenries (μH) or millihenries (mH).
What is the purpose of a variable inductor?
To allow adjustment of inductance in tuning and matching circuits.
What is the Q factor of an inductor?
The quality factor, representing the efficiency of the inductor in terms of energy storage versus energy loss.
What is the role of inductors in filtering circuits?
They block high-frequency signals while allowing low-frequency or DC signals to pass.
What is an RF choke?
A type of inductor designed to block high-frequency signals in radio frequency circuits.
What is a power inductor?
An inductor designed to handle high currents in power supply circuits.
How are inductors used in LC circuits?
They form resonant circuits with capacitors to filter or tune specific frequencies.
What is the effect of increasing the number of turns in an inductor coil?
It increases the inductance by strengthening the magnetic field.
What is the role of the core material in an inductor?
To concentrate the magnetic field and increase inductance.
How do you calculate the inductance of an air-core inductor?
Using the formula L = (N^2xA)/l, where N is the number of turns, A is the cross-sectional area, and l is the length.
What is the self-resonant frequency of an inductor?
The frequency at which the inductance and parasitic capacitance resonate, limiting the inductor’s effectiveness.
What is a common application of inductors in power supplies?
To smooth out voltage ripple and store energy in switching regulators.
What is a flyback inductor?
An inductor used in flyback converters to store energy and transfer it to the output during the off phase.
How do temperature changes affect inductors?
They can alter the core’s magnetic properties, affecting inductance and performance.
What are common problems with inductors?
Core saturation, overheating, and high-frequency losses.
What is core saturation in an inductor?
When the core material cannot support additional magnetic flux, reducing inductance.
How do you test an inductor?
Use an LCR meter to measure inductance, resistance, and Q factor.
What is a coupled inductor?
Two or more inductors wound on the same core, used in transformers and filters.
What is a shielded inductor?
An inductor with a magnetic shield to reduce electromagnetic interference.
What is the purpose of a bypass inductor?
To bypass unwanted high-frequency signals to ground.
What is the typical frequency range for inductors?
From a few kHz to several GHz, depending on the type and application.
How do inductors improve energy efficiency in circuits?
By storing and releasing energy with minimal losses in power supplies and filters.
What is the parasitic resistance of an inductor?
The resistance of the wire used in the coil, which can cause power loss.
How do you select an inductor for a circuit?
Consider the inductance, current rating, core material, Q factor, and frequency requirements.
