What is a power inductor?
A power inductor is a passive electronic component which stores electrical energy in the form of magnetic energy. It is basically a coil which is made from wire that stores electrical energy in an electric field which is created by the current which flows in the coil. The ability of power inductor of storing energy in the form of electric field is measured in the henry. It is names henry after the scientist who discover the principle of inductance.
Working principle of power inductor
(What is a Power Inductor?)
Power inductor works on the base of faraday’s law of electromagnetic induction. According to faraday’s law of electromagnetic induction whenever change comes in the magnetic field of the wire produces a voltage or electromotive force (emf). When electric current passes through the coil, a magnetic field produces around it which stores electrical energy in the form of magnetic flux, the magnetic flux is proportional to the current which flows in the inductor. Whenever the current through the inductor changes the magnetic field changes which produces the electromotive force in the inductor.
Now according to Lenz’s law, the voltage which is produced due to change in the magnetic field in the inductor opposes the cause by which it produces. Power inductors are used in different applications which will be discussed below.
Energy store in inductor is Mathematically expressed as
W = ½ LI2
Here
- W expresses the energy store in the inductor which is measured in “Joules” and denoted by “J”.
- L expresses the inductance of the inductor which is measured in “Henry” and denoted by “H”.
- I express the current in the inductor which is measured in “ampere” and denoted by “A”.
What is faraday’s law of electromagnetic induction?
It is a basic law of electromagnetism which tells how magnetic fields interact with an electric circuit and create voltage or electromotive force (emf). This process in which emf is produced is called electromagnetic induction. Faraday’s law of electromagnetic induction stated that whenever changes come in the magnetic field of a coil, an emf will induce in the coil. The induced emf will be proportional to the rate of change in the magnetic field.
What is Lenz’s law
It is a basic law of electromagnetism which tells how a magnetic field interacts with electric circuit or current and produces voltage or electromotive force (emf). It is stated as the direction of an emf which is produced due to changing magnetic field will be opposite to its caused.
Application of power inductor
(What is a Power Inductor?)
- Switching regulator step down circuit: it is an application of power inductor which uses IC, power inductor and capacitor for the purpose of converting a DC input voltage to the desired output voltage. Power inductor store energy in the form of magnetic field and release it when this energy is required.
- Power factor correction: power inductor also finds applications if power factor correction. It is used in power factor correction circuit to improve the performance of the power supply. It is also used to filter out the high frequency noise and smooth the output voltage.
- DC to DC converter: it is used in DC-to-DC converter for step-up and step down the level of voltage.
- Filter: it is used in filter to remove unwanted frequency. It is also used in low pass filter, high pass filter and band pass filter.
Power inductors also serve different important function which includes
- It is used in filtering, energy storage and voltage regulation.
- It is used in filter for analog circuit and used for signal processing.
- It can be used as a low pass filter too.
Types of power inductor
(What is a Power Inductor?)
There are different types of power inductor available in the market in which each has its own different properties.
- Iron core power inductor: the core of this type of power inductor is made from iron. It is used when high inductance and low resistance are needed. Iron core power inductor finds application in power supplies.
- Air core power inductor: the core of this type of power inductor is made of air. It is used when low inductance and high resistance is needed. Air core power inductors find application in radio frequency circuits.
- Powdered iron core power inductor: its core is made from powder and used when high inductance and low resistance is needed. It is suitable for low frequency applications.
- Ferrite core power inductor: its core is made from ferrite and used when high inductance and low resistance are needed. Ferrite core power inductors find applications in high frequency.
- Variable power inductor: its core is variable that can be adjusted to change the inductance. It is used when variable inductance is needed. It is mainly used in radio tunning circuits.
- Audio frequency power inductor: it is used in audio frequency circuit and used when low resistance and high inductance is needed.
- Radio frequency power inductor: it is used in radio frequency circuits and suitable when high inductance and low resistance is needed.
Advantage of Power Inductor
- It can be operated in any condition because they are robust.
- They are very cheap in price.
- They don’t need any maintenance.
Disadvantage of Power Inductor
- It can produce heat when current is flowing in them due to this energy loss can occur.
- It can be heavy and bulky which can make them uncomfortable for many applications.
- It produces EMI noise.
Comparison of power inductor and regular inductor
| Parameters | Power inductor | Regular inductor |
| Inductance | Th inductance value of power inductor is high. | The inductance value of regular inductor is low. |
| Current rating | The current rating of power inductor is high. | The current rating of regular inductor is low. |
| Size | The size of power inductor is large. | The size of regular inductor is small. |
| Cost | Power inductor is expensive as compared to regular inductor. | Regular inductor is cheap is compared to power inductor. |
How do I test my inductor on multimeter?
To test your inductor on multimeter, here are the steps.
- First, set the multimeter to ohmmeter setting.
- Connect the probes of the multimeter to the inductor.
- Use the resistance function of the multimeter to measure the inductance of the inductor.
- Use the diode test function of the inductor to verify that the inductor is free of shorts.
Now if the inductor measures very low resistance it means the inductor is working properly, but if it measures very high resistance value it means the inductor is not working properly.
How to choose an inductor for your circuit?
To choose inductor for your circuit follow the following steps.
- Find the inductance value: find the required inductance value of inductor, it can be determined from the circuit diagram or use the recommended value of CAD Software.
- Measure the maximum current: add output current and one half of the raffle current to find maximum current.
- Select the inductor: if the calculated value is equal or close to it and maximum current rating is greater or equal to the calculated maximum current rating then select that inductor.
- Consider another parameter also: other parameters include size, cost and temperature range. These parameters should be considered when selecting an inductor.
See Also:
Frequently asked question
Q1: What is a power inductor?
Ans: it is a passive component which stores energy in the form of magnetic field when electrical current flows in it.
Q2: how power inductor works?
Ans: power inductor works in the bases of faradays law of electromagnetic induction, which state that whenever change comes in magnetic field of a coil then emf will induce in the coil.
Q3: What are the applications of a power inductor?
Ans: power inductor is used in different application which includes:
- It is used in power supplies.
- It is used in filters and transformers.
- It is also used in electronic circuits to store energy and to remove fluctuation from voltage to smooth it.
Q4: what is inductance in power inductor?
Ans: it is the property of an inductor to oppose any change in current.
Q5: what is the unit of inductance?
Ans: the SI (system international) unit of inductance is Henry which is denoted by (H).
Q6: what is the main difference between power inductors and regular inductors?
Ans: the main difference between power inductor and regular inductor is that the power inductor is design to handle high current and it have a high value of inductance while the regular inductor is design to handle low current and have low value of inductance.
Q7: what is the maximum current rating of power inductor?
Ans: the maximum current rating of power inductor is dependent on:
- Inductance value of the inductor.
- Core materials of the inductor.
- Temperature range of the inductor.
Q8: what is the difference between inductance and resistance?
Ans: the main difference between inductance and resistance is:
- Inductance is the property of components to oppose any change in the current.
- Resistance is the property of the components to resist the flow of current.
Q9: what is the difference between power inductor and capacitor?
Ans: the main difference between capacitor and power inductor is:
- Inductor store energy in the form of magnetic field.
- Capacitor store energy in the form of electric field.
Q10: What is the purpose of a power inductor?
Ans: inductors are mainly used for choking, blocking and to store and transmit energy in power converters.
Q11: what is inductor in simple words?
Ans: it is a passive component with two terminals which is used to store energy in the form of magnetic field.
Q12: Do inductor block AC or DC?
Ans: inductor does not block DC, it passes DC and generates impedance to AC.
Q13: what is an inductor formula?
Ans: the formula of inductor is:
V= l (di / dt)
V is voltage and L is inductance
