Inductors: making high voltage from low voltage

Summary

This video explores the fascinating world of inductors, focusing on their application in DC to DC converters, particularly in generating high negative voltages from low positive ones. The host delves into the theory and practical experiments, explaining how inductors store energy in a magnetic field and resist changes in current. A step-by-step demonstration shows how an inductor can boost voltage, using a simple circuit with a switch, resistor, and capacitor. The video also highlights the impact of pulse frequency on output voltage, culminating in a high-voltage output from a low-input voltage, showcasing the power of electronic components in circuit design.

Takeaways

• 🔌 Inductors are used in DC to DC converters to step up or convert low positive voltage to high negative voltage.
• 🧲 Inductors store energy in a magnetic field and release it when needed, similar to how capacitors store energy in an electric field.
• 📏 The two key parameters of an inductor are its inductance (measured in Henry) and the maximum current it can withstand (measured in Amperes).
• 🔍 An LCR meter is used to measure the inductance value of inductors, which can range from microhenries to millihenries.
• 🪵 The core material of an inductor, such as ferrite or iron, significantly increases its inductance compared to a simple wire winding.
• 🔗 Inductors resist changes in current; they act as an open circuit when current starts to flow and as a short circuit when the current is steady.
• ⚡ Boost regulators utilize the inductor's resistance to current change to momentarily create a voltage higher than the source voltage.
• 🔄 A diode and capacitor are used in conjunction with an inductor to capture and maintain the high voltage generated.
• 🤖 Electronic switches can replace manual button pressing in circuits, allowing for faster and more precise control of voltage boosting.
• 🎥 The video demonstrates practical experiments showing how inductors can be used to generate voltages much higher than the input, showcasing the power of electronic components.

Q & A

What is the primary function of an inductor in electronics?

An inductor's primary function is to store energy in the form of a magnetic field and release it when needed in the circuit.

What are the two most important parameters to consider when using inductors?

The two most important parameters are inductance, measured in Henry and symbolized by L, and the maximum current the inductor can withstand, symbolized by I and measured in amperes.

How does the presence of a core made of ferrite or iron affect the inductance of an inductor?

The presence of a core made of ferrite or iron greatly increases the inductance of an inductor because these materials can get magnetized, helping the inductor store more energy in the form of a magnetic field.

What is the difference between how a capacitor and an inductor store energy?

A capacitor stores energy in the form of an electric field, while an inductor stores energy in the form of a magnetic field.

How does an inductor resist changes in current?

An inductor resists changes in current by trying to maintain a constant current flow through it. When current flow is initiated or stopped, the inductor resists this change, which can be used to create a voltage boost.

What is the role of a diode in a voltage booster circuit involving an inductor?

In a voltage booster circuit, a diode allows the high voltage generated by the inductor to charge a capacitor but prevents the capacitor from discharging through the resistor, thus saving the high voltage.

How can an inductor be used to create a voltage higher than the source voltage?

An inductor can be used to create a higher voltage than the source by resisting the change in current when a switch is opened, forcing the current to flow through a resistor, which results in a higher voltage across the resistor according to Ohm's law.

What is the purpose of using an electronic switch instead of a manual switch in a DC to DC converter circuit?

An electronic switch can toggle at a much higher frequency than a manual switch, allowing for more rapid and precise control over the charging and discharging of the inductor, thus enabling more efficient voltage conversion.

How does the frequency of pulses impact the output voltage in a DC to DC converter circuit?

The frequency of pulses can greatly impact the output voltage by affecting how often the inductor charges and discharges. Higher frequencies can lead to higher output voltages, as seen in the script where an 80-volt output was achieved from a 0.5-volt input at a pulse frequency of 5 kHz.

What is the significance of using a PNP type or P Channel transistor in a DC to DC converter circuit?

In a DC to DC converter circuit, using a PNP type or P Channel transistor is beneficial when the switch is on the high side of the power supply. This configuration allows for effective control of the circuit's power flow and switching.

Outlines

00:00

🔌 Understanding Inductors in Electronics

This paragraph introduces the concept of inductors, highlighting their use in DC to DC converters, particularly for generating high negative voltages from low positive ones. The presenter aims to demystify inductors by explaining their function and importance in electronics. An inductor is described as a coil of wire that stores energy in a magnetic field and releases it when needed. The two key parameters of an inductor are inductance, measured in Henry (L), and the maximum current it can withstand, measured in amperes (I). The presenter uses an LCR meter to demonstrate how the inductance of a coil changes when a ferrite or iron core is introduced, significantly increasing its inductance. The fundamental behavior of an inductor is also explained, where it resists changes in current flow, which is crucial for understanding how they can be used to boost voltages in circuits.

05:01

🔋 Boosting Voltages with Inductors

The second paragraph delves into how inductors can be utilized to create voltage booster circuits. It explains the behavior of an inductor when a switch in a circuit is opened, and how it tries to maintain the current flow, resulting in a sudden increase in voltage across a resistor. This principle is used to create a high voltage from a lower source voltage. The paragraph further discusses the use of a diode and capacitor to capture and maintain the high voltage. A practical demonstration is provided, where the presenter sets up a circuit to show the increase in voltage across a capacitor when the inductor's current is suddenly stopped. The concept is then expanded by introducing an electronic switch in the form of a transistor to automate the process, resulting in a much higher and controlled output voltage. The experiment concludes with an oscillator being used to automate the switching process, demonstrating a significant increase in output voltage from a low input voltage.

10:01

🎥 The Power of Pulses in Electronics

The final paragraph wraps up the video by showcasing the impact of pulse frequency on output voltage in an inductor-based circuit. It emphasizes the beauty and potential of electronics through the use of components like inductors. The presenter demonstrates that with a frequency of 5 kHz, it's possible to achieve an output voltage of 81 volts from an input of just 1.2 volts. The paragraph concludes with a call to action for viewers to like and subscribe for more content, thanking them for their engagement and setting the stage for future videos.

Keywords

💡Inductors

Inductors are electrical components that store energy in a magnetic field when an electric current flows through them. In the context of the video, inductors play a crucial role in DC to DC converters, particularly in boosting voltage levels. The video script explains that inductors resist changes in current, which is key to their function in voltage boosting circuits. An example from the script is the demonstration of how an inductor can be used to generate a high negative voltage from a low positive voltage.

💡DC to DC Converters

DC to DC converters are electronic circuits that convert one voltage level from a DC power source to another. The video focuses on a specific application of these converters, where an inductor is used to convert a low positive voltage to a high negative voltage. The script describes how inductors, with their ability to resist current changes, are essential in creating such converters.

💡Boost Regulators

Boost regulators are a type of DC to DC converter that increases the output voltage to a level higher than the input voltage. The video script introduces boost regulators as part of the explanation of how inductors can be used to increase voltage. The practical experiment in the video demonstrates the boost regulator's function using an inductor, a switch, and a resistor.

💡Inductance

Inductance is a measure of an inductor's ability to store energy in a magnetic field and is measured in henries (H). The script mentions inductance as one of the most important parameters of an inductor, with examples given such as 1.2 microhenry and 9.8 microhenry. The video also shows how the inductance value can be measured using an LCR meter.

💡Magnetic Field

A magnetic field is a vector field that describes the magnetic influence of electric charges in relative motion and magnetized materials. In the video, inductors are described as storing energy in the form of a magnetic field. The script explains how the presence of a ferrite or iron core in an inductor can greatly increase its inductance by enhancing the magnetic field.

💡LC Meter

An LC meter, also known as an inductance-capacitance-resistance meter, is an instrument used to measure the inductance of inductors. The video script includes a demonstration of using an LCR meter to measure the inductance of different inductors, illustrating the practical application of such a device in testing and verifying the properties of inductors.

💡Current

Current refers to the flow of electric charge in a circuit, which is the central concept in understanding how inductors work. The video script describes how inductors resist changes in current, using this property to create voltage boosts. The script provides a practical example of how, when a switch is closed, the current through an inductor starts at zero and gradually increases, demonstrating the inductor's behavior.

💡Voltage

Voltage, or electric potential difference, is the driving force that pushes electric charge through a circuit. The video's theme revolves around using inductors to manipulate voltage levels, particularly to create a higher output voltage from a lower input voltage. The script includes an experiment where the voltage is boosted from 12 volts to over 100 volts using an inductor.

💡Resistor

A resistor is a passive component that opposes the flow of electric current in a circuit. In the video, a resistor is used in conjunction with an inductor to demonstrate how the inductor's resistance to current change can be harnessed to create a higher voltage across the resistor. The script explains the role of the resistor in the voltage boosting process.

💡Diode

A diode is a semiconductor device that allows current to flow in one direction only. In the video, a diode is used in the voltage boosting circuit to allow the high voltage generated by the inductor to charge a capacitor while preventing the capacitor from discharging back through the resistor. The script describes the diode's role in maintaining the high voltage across the capacitor.

💡Capacitor

A capacitor is a component that stores energy in an electric field. In the video, a capacitor is used to save the high voltage generated by the inductor. The script explains that without a diode, the capacitor would discharge through the resistor, but with the diode in place, the capacitor can hold the high voltage, demonstrating the capacitor's role in energy storage.

Highlights

Inductors are used in DC to DC converters, especially for converting low positive voltage to high negative voltage.

Inductors store energy in the form of a magnetic field and release it when needed in the circuit.

Inductance is measured in Henry and is symbolized by the uppercase letter L.

The maximum current an inductor can withstand is symbolized by the uppercase letter I and measured in amperes.

An LCR meter is used to measure the inductance value of inductors.

Even a simple wire has inductance, though it may be too low to measure with instruments.

Inductors with ferrite or iron cores have higher inductance due to their ability to be magnetized.

Inductors resist changes in current passing through them, acting as an open circuit initially and a short circuit later.

Inductors can be used to create voltages higher than the source voltage by resisting current changes.

A diode and a capacitor can be used to save the high voltage generated by an inductor.

An electronic switch can be used to rapidly press and release a circuit, achieving higher voltages than humanly possible.

A transistor can replace a mechanical switch in a circuit for more efficient voltage boosting.

An oscillator can be used to generate switching pulses at a specific frequency to control the transistor.

The frequency of pulses can greatly impact the output voltage in a voltage boosting circuit.

The video demonstrates creating 81 volts output from a 1.2-volt input using an inductor-based circuit.

The video concludes by emphasizing the beauty and potential of electronics through the use of inductors.

Transcripts

have you ever thought about inductors

inductors have several applications in

electronics but one of my favorites is

DC to DC converters especially

converting a very low positive voltage

to a high negative voltage in this video

I'll show you how an inductor can help

us to create a negative voltage

generator through a delicious mix of

theory and practical experiments after

watching this video you will understand

how how boost Regulators work and why we

need inductors and pulses in some

switching Regulators stick around till

the end for some surprising

twists inductors are used to store

energy in the form of a magnetic field

and relays that energy when needed in

the circuit right this definition is not

very clear let me introduce inductors to

you from my own point of view after that

I'll show you how inductors enable us

toe increase voltage inductors are

nothing but wire

windings this is a schematic symbol of

an inductor and these are real inductors

look inductors have many parameters but

two of them are the most important to

consider first the inductance which is

measured in Henry and symbolized by the

uppercase letter L for example one micro

Henry 10 Micro Henry Etc and the second

the maximum current that the inductor C

with the stand which is symbolized by

the uppercase letter I and measured in

ampers like 1 Amper 2 Amper

Etc this is an LCR meod which is able to

measure the inductance value of these

inductors

look this inductor has inductance value

of 1.2 microhenry

and this inductor has inductance value

of 9.8

microhenry even this simple wire winding

has inductance look it has an inductance

value of about 0.4 microhenry you may

wonder if I say that even this piece of

wire is actually an inductor and has

inductance however its inductance is too

low to be measured using instruments

like this one inductors have a core made

of ferite or iron which greatly increase

their inductance we can test it it will

be a really awesome experiment the

inductance value of the simple winding

was 0.4 micro now I'm going to use this

Steel Road when I dip this Steel Road

into the

winding the inductance of the winding

increases now it's 5.8

microen now it's

9.8

microhenry and now it's 11.6 microhenry

because this iron Road can get

magnetized and help the inductor store

more energy in the form of a magnetic

field inside the road inductors store

energy like capacitors but an inductor

stores energy in a form of a magnetic

field while a capacitor stores energy in

the form of an electric field even

though these definitions are correct

they are boring right through these

definitions away I'm going to give you

better definitions a capacitor tries to

keep the voltage at a point in a circuit

constant and an inductor tries to keep

the current passing through it constant

or in another word a capacitor resists

voltage change across itself and an

inductor resists to the current change

passing through itself these definitions

will make understanding these components

easier inductors like this one resist

changes in the current passing through

them so if you close this switch at the

first moment the current flowing through

this inductor will be zero because the

current flowing through this inductor

was Zero before closing the switch this

means the impedance of this inductor is

infinite at the first moment actually

this inductor is an open circuit at the

first moment over time the current Cur

will flow through this inductor and

gradually increase remember we are

talking about micro or even nanocs after

a certain amount of time the impedance

of this inductor will approach zero at

this moment this inductor is a short

circuit so the amount of current flowing

through this inductor will reach 12

ampers there was nothing special so far

it was the natural behavior of inductors

now answer this question how can we use

this feature of inductors to boost

voltages inductors have the ability to

resist current changes and this feature

helps us use them in a voltage booster

circuit just think about the moment you

open the

switch suppose the switch is closed and

now this inductor is fully charged and

is a short circuit so this resistor is

out of the circuit due to the short

circuit here I mean we can ignore this

resistor and the current flowing through

this inductor is 12 ampers now if you

suddenly open this switch this inductor

will try to resist the change in the

current amount flowing through it so at

the first moment after opening the

switch the current flowing through this

inductor will remain 12 ampers this 12

ampere current has no way to pass except

through this 10 Ohm resistor like this

by applying simple ohms law we can see

that at the moment after opening the

switch the voltage across this resistor

will be 100 20 volts which is 10 times

higher than 12v battery running the

circuit wasn't that interesting it was

fascinating right so it's worth liking

the video right thank you anyway this is

how an inductor helps us create voltages

higher than the source voltage however

over time the current flowing through

the inductor will gradually decrease but

we can use a diode and a capacitor to

save the high voltage now now we have a

variable voltage here that starts from

120 volts and gradually decreases until

it reaches zero because the inductor

current is decreasing actually the

energy saved in this inductor will be

dissipated in this resistor we can add a

capacitor here to save the voltage but

if you connect the capacitor directly in

parallel with this resistor as the

voltage across this resistor decreases

the voltage across the capacitor will

decrease too so we need to add a diode

somewhere here to allow the voltage to

charge the capacitor but prevent the

capacitor from discharging through this

resistor I'm going to set up this

circuit and test it

[Music]

look when I press and release the button

the voltage at the capacitor increases

now the voltage across the capacitor is

15 volts 40 volts which is five times

higher than the three volt input voltage

if I press and release the button

rapidly I can achieve even more voltage

look now the voltage across the

capacitor is

32

29 35 36

38

volts I can't press and release the

button faster than what you saw because

I'm human and my body has limitations

but an electronic switch can do it

thousands of times faster than me so why

not to use an electronic switch to test

the circuit I'm going to use a

transistor instead of this

switch if you look attentively the

switch is on the high side of the power

supply it's here not here so it's better

to use a PNP type or P Channel

transistor in this experiment I'm going

to use

a1015 which is a PNP type BJT in this

circuit we need an oscillator to turn

this transistor on and off at a specific

frequency here I'm going to use my

function generator to generate switching

pulses and I will apply switching pulses

to point a

I

[Music]

[Music]

look at these numbers now the input

voltage is 1.2 volts and the output

voltage is 81 volts this is really

awesome by the way the frequency of

pulses can greatly impact the output

voltage now the frequency of pulses is 5

khz it was very easy to make a 80 volts

out of 0.5 volts right this is why I

love Electronics because of these

amazing component and experiments you

have seen one of the beauties of

electronics in this video where an

inductor wins an Oscar for the leading

Ro anyway we have reached the final

moment of this video thanks for watching

if you want to see more videos like this

one make sure to like this video And

subscribe to my channel see you in the

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