Voltage, Current, and Power Explained - Laying the Foundation for Basic Circuits | Basic Electronics

Summary

This tutorial aims to simplify the complex world of circuits by focusing on foundational concepts like voltage and current, using analogies to make them intuitive. It clarifies common misconceptions and emphasizes the importance of understanding the difference between power and energy. The goal is to provide a solid foundation for further study in electronics, with practical insights that highlight the significance of voltage and current in circuit analysis.

Takeaways

• 🌟 The tutorial series aims to teach the basics of circuits, focusing on understanding concepts rather than complex math.
• 🔋 Voltage is the potential difference that drives the movement of electrons, often compared to the potential energy of water at different heights.
• 💧 Current represents the flow of electrons, similar to the flow of water when a glass is tipped.
• 🔌 It's common to misuse the terms 'voltage' and 'current'; voltage is across a component, whereas current is through it.
• ⚠️ Misunderstanding the difference between voltage and current can lead to incorrect assumptions about electrical systems.
• 🔥 High current values, such as amps, are more impressive and potentially dangerous than high voltage values.
• 🔌 The speaker emphasizes the importance of distinguishing between 'volts across' and 'amps through' a component.
• 🔄 Power is the rate at which work is done, a combination of voltage and current, and is different from energy.
• ⏳ Energy is the capacity to do work and is often considered in terms of power over time, or energy per second.
• 🔌 In circuits, power is more commonly the focus, but energy becomes important when dealing with components like capacitors.
• 📚 The tutorial encourages learning the foundational concepts of voltage and current for circuit analysis and to check out additional resources for a deeper understanding.

Q & A

What is the main goal of the tutorial series on circuits mentioned in the script?

The main goal is to provide an understanding of circuit concepts from the beginning to the end, focusing on intuitive understanding rather than complex math, so that viewers can have a good feel for what circuits do.

Why is it incorrect to say 'volts through something' instead of 'volts across something'?

It's incorrect because 'volts through something' implies current, which is the flow of electrons. 'Volts across something' correctly refers to the potential difference or voltage potential between two points.

What is the difference between voltage and current according to the script?

Voltage is the potential energy difference or desire for electrons to move from one place to another, while current is the actual flow of electrons, like the movement of water when a cup is tipped.

What is the water analogy used to explain voltage and current?

The water analogy compares voltage to water at a higher level wanting to flow down due to potential energy, and current to the actual flow of water when it moves from the higher level to the lower level.

Why are bigger numbers in amps more impressive than bigger numbers in volts?

Bigger numbers in amps are more impressive because they represent a larger flow of electrons, which can produce significant effects, like melting wires, whereas high voltages can be managed without such dramatic effects.

What is the basic difference between power and energy as explained in the script?

Power is the rate at which work is done or energy is transferred, often measured in watts, while energy is the capacity to do work, often measured in joules or watt-hours.

Why are capacitors said to have a high power density but not necessarily a high energy density?

Capacitors can release current very quickly, which means they can produce a lot of power in a short time, but they don't hold much energy, so their energy density is lower compared to a battery that can sustain power over a longer period.

What are the two most important concepts in circuit analysis according to the script?

The two most important concepts are voltage and current, as the majority of circuit analysis involves solving for voltage across components or current through components.

What is the significance of understanding the difference between voltage and current in circuit analysis?

Understanding the difference is crucial because it affects how one interprets and calculates the behavior of circuits, including power calculations and the ability to predict circuit performance.

Why does the script emphasize the importance of not confusing current and voltage?

Confusing current and voltage can lead to incorrect assumptions and calculations in circuit analysis, which is critical for designing and understanding the performance of electrical systems.

What additional resource is mentioned in the script for further learning about circuits?

A written tutorial on circuitbred.com is mentioned as an additional resource that provides a different perspective and more in-depth explanations of some concepts.

Outlines

00:00

🔌 Understanding Circuits: Current and Voltage Basics

This paragraph introduces the series of tutorials on circuits, emphasizing the importance of understanding basic concepts without delving too deep into complex math. The speaker clarifies the common confusion between current and voltage, using the water analogy to explain voltage as potential energy and current as the flow of electrons. The distinction is made clear that voltage is the potential for movement, while current is the actual movement. The speaker also points out that high current values are more impactful than high voltage values in everyday electronics, using a personal anecdote about an electromagnet project to illustrate this point.

05:02

🔋 Power and Energy in Circuits: Clarifying the Differences

The second paragraph delves into the concepts of power and energy, explaining that while they are often used interchangeably, they are fundamentally different. Power is described as the rate at which work is done, a product of voltage and current, and is illustrated with the analogy of a water wheel spinning due to the flow of water. Energy, on the other hand, is the capacity to do work and is often measured over time. The paragraph further explains the difference between power density and energy density, using capacitors as an example of high power density and batteries as an example of high energy density. The speaker stresses the importance of understanding these concepts for circuit analysis, particularly for upcoming lessons.

Keywords

💡Circuits

Circuits are the fundamental components of electronic systems, consisting of a closed loop that allows electrons to flow through. In the video, the theme revolves around understanding circuits from the basics to more complex concepts without delving too deep into the math. The script discusses the importance of grasping the fundamental concepts of circuits to build an intuitive understanding of how they function.

💡Current

Current refers to the flow of electric charge, typically measured in amperes (amps). It is a central concept in the video, where the script explains that current is the actual movement of electrons through a circuit element, using the analogy of water flowing from a tipped glass to illustrate this concept.

💡Voltage

Voltage is the electrical potential difference between two points, measured in volts. The script emphasizes the difference between voltage and current, explaining that voltage is the 'desire' for electrons to move from one point to another, akin to the potential energy of water at a higher elevation.

💡Water Analogy

The water analogy is a teaching tool used in the script to explain the concepts of voltage and current. It likens voltage to the potential energy of water at a higher elevation and current to the flow of water when it is released, helping to intuitively understand these electrical concepts.

💡Potential Energy

Potential energy, in the context of the video, is related to voltage and is the energy that an electrical system possesses due to the position of charged particles. The script uses the water analogy to describe voltage as the potential energy difference, which drives the flow of electrons.

💡Power

Power is the rate at which work is done or energy is transferred, and it is a measure of the combination of voltage and current. The video script explains that power is not just about the potential (voltage) but also the actual flow (current) that can do work, such as spinning a paddle wheel in the water analogy.

💡Energy

Energy, in the video, is the capacity to do work and is often confused with power. The script clarifies that energy is the total amount of work that can be done over time, whereas power is the rate at which that work is done, with the example of a capacitor being able to release energy quickly (high power density) but not holding much energy (low energy density).

💡Electromagnet Project

The electromagnet project mentioned in the script serves as a practical example to illustrate the difference between high current and high voltage. It demonstrates the potential dangers of high current, as evidenced by the melting of leads when only three amps were passed through them.

💡Embedded Systems

Embedded systems are computer systems designed for specific control functions. The script touches on the typical current levels dealt with in embedded systems, which are often in milliamps or microamps, contrasting with the higher current levels that can be managed in power grid distribution.

💡Capacitors

Capacitors are electronic components that store energy in an electric field. The script explains the distinction between power and energy in the context of capacitors, noting that while they may not hold a lot of energy, they can release it very quickly, demonstrating high power density.

💡Battery

A battery is a device that stores chemical energy and converts it into electrical energy. In the video, the script uses the battery as an example of a device with high energy density, meaning it can sustain the release of energy over a longer period, though it may not release as much energy as a capacitor in a very short time.

Highlights

Introduction to a series of tutorials on basic circuits, aiming to cover the subject from start to finish.

Emphasis on understanding circuit concepts intuitively rather than focusing solely on complex math.

Clarification of common misconceptions between current and voltage, highlighting their differences and importance.

Voltage defined as the potential energy difference, like water at different heights, driving the desire for electrons to move.

Current described as the flow of electrons, analogous to the flow of water when a glass is tipped.

Explanation of how voltage and current relate within a circuit, with voltage across an element and current through it.

Misuse of terms like 'volts through something' corrected to 'volts across something'.

The significance of higher amperage being more impressive than higher voltage in practical circuits.

Personal anecdote about the dangers of high current in an electromagnet project, leading to melting leads.

Comparison of high voltage power lines to the rarity of dealing with high amperage in everyday electronics.

Introduction to the difference between power and energy, with power being the rate of doing work.

Power defined as a combination of potential and flow, necessary to turn a mechanical device like a wheel.

Energy explained as the total amount of work that can be done, often confused with power but distinct.

The role of capacitors in holding little energy but releasing it quickly, demonstrating high power density.

Batteries' ability to sustain energy release over time, showing high energy density despite lower instantaneous power.

Importance of understanding voltage and current for circuit analysis, which will be the focus of upcoming lessons.

Invitation to join the rest of the basic circuits tutorials for a comprehensive learning experience.

Recommendation to visit circuitbred.com for a written tutorial offering a different perspective and deeper explanations.

Transcripts

[Music]

we wanted to create a

series of tutorials about circuits one

basically go over

circuits one from the beginning to the

end so even if we don't get into the

crazy math that you're going to run into

into your college courses or your high

school courses

you'll at least understand the concepts

and we will do some math but i don't i

think we're going to focus more on

making it so you can intuitively

understand so when you look at a circuit

you kind of have a good feel for what

it's going to be

versus how do i crunch the numbers on

this one so with that

i would first like to jump into before

we get into anything

some of the basic terms that i hear and

some of the ways that those terms are

misused

and um confused all of the time so in

circuits you're going to hear

current and voltage a lot and those are

confused all the time and they're very

very different they're related but

they're very very different

so with current and voltage voltage is

the desire for

electrons to move from one place to

another it's a voltage potential it's

the potential energy difference

between two different spots the way i

like to think of it and the way you'll

hear many people discuss it is using the

water analogy

and that's sort of like if you have

water up here and water down here

the water up here wants to flow down

here but if you have like a cup of water

up here

and it's not flowing down here you don't

have any flow but it's still at that

higher potential

so that's voltage in terms of that

desire that potential

for this to move down to here now

current using that water analogy would

be if i were to tip the glass

in that flow of water that flow of

electrons

would be that movement of electrons and

that would be current

now when you have a circuit you have a

voltage across

something and you have a current through

things and that's because you have that

potential

across something saying i want to have

a flow there but not necessarily have

that flow whereas the current

is the actual flow through that circuit

element

just like with the cup of water having a

cup of water up here

you have that voltage potential but it's

not until you turn it

that you actually have the flow and i

don't know why it's such a pet peeve for

me

but it drives me crazy to hear somebody

say volts through something

yeah that's got 10 bolts through it oh

it doesn't have 10 bolts through it has

10 volts across it

you might have 10 milliamps through it

but it has 10 volts across it now one

quick thing and this is something you

don't get an intuitive feel of

in most circuits but usually bigger

numbers in amps are more impressive than

bigger numbers

in volts so i was actually doing an

electromagnet project with my daughter

since

all the schools are closed right now and

i put my leads on this thing and it

had about three amps going through it

and that was enough for my leads to

start melting again and i had to pull it

and

pull the the melted wire out or excuse

me the wire out of the melted plastic

and that was only three amps

where those same leads i can put across

120 volts

and not have any problems with that so

that's something you'll hear

the high power lines those are thousands

and tens of thousands of volts

whereas if i were to hear something had

tens of thousands of amps

i would be terrified out of my mind

because i usually only deal with stuff

that has

less than an amp other people they can

deal with it in power grid

distribution all that sort of stuff but

for most projects you're dealing with if

you're seeing anything over a couple of

amps

that's a really big number whereas you

can get into 100 volts without

breaking too much of a sweat so that's

just something again when you're working

on stuff

in circuits they don't really care

they're just going to make the math

whatever makes sense and what is

ever either easy or hard but when in

real life if you're dealing especially

with embedded systems and electronics

small numbers for current are more

normal in the milliamps or microamps

versus the amps or tens or hundreds of

amps

with that out of the way let's jump into

the difference between power

and energy and first let's just talk

about what power is

so when i was talking about taking that

glass

and pouring it there's a certain amount

of power if we had a

paddle wheel here and we were to pour

the water and

maybe had the paddle wheel down here

that water would pick up velocity and be

able to spin the wheel

and that combination of both the

potential

and the flow is the power that turns

that wheel

and it's also something where if you

notice

uh if you take a glass up here and

there's no flow there's no power because

it's just

sitting up there so that is a zero power

situation

whereas if i were to take a glass of

water and gently spill it

across this table there would also be no

power basically no power because

there's no voltage you're getting that

flow across here but there's no way to

really

turn a turbine or turn any sort of wheel

off of that

and so power is a factor of both

voltage and flow current

to be able to do work with that power so

power and energy are frequently used

interchangeably but that is totally

incorrect power is a function of

energy over time usually energy per

second

so you can get something that has a lot

of power at that one moment but there's

not a huge amount of overall

energy or you can have something that

has a huge amount of overall energy

but isn't able to actually produce much

power and

95 of what you do in circuits is going

to be power and that's really all you're

going to worry about

but if you start working with things

like capacitors that's where

the difference makes a difference

because

capacitors they don't hold very much

energy you can't

get much out of them but they can

release current

incredibly fast much faster than a

battery so you can say that a capacitor

has an incredibly high power density

because it can produce a ton of energy

in a very short period of time

compared to a battery which can produce

only a fraction of

a fraction of the amount of energy in

that same period of time

but it can sustain it for much much

longer and so it has a much higher

energy density

because you can get overall much more

work done with the battery than with the

capacitor

even though you can't get as much out at

the same time so those are the basic

four things that you need to worry about

and really of these four the two most

important things in the next

classes and the next lessons are going

to be voltage and current the vast

majority of your circuit analysis is

going to be to solve

for voltage across something or current

through something that is going to be 95

of what you're doing over the next

couple of months so

make sure that you know what those are

and the difference between them and you

should be good to go

i hope that was helpful i hope that set

a foundation that you enjoyed this

enough that you'll come and join us for

the rest of this basic circuits classes

and basic circuits tutorials

i think it's going to be a lot of fun i

think we're going to learn a ton of

stuff as always we put a written

tutorial up on circuitbred.com link in

the description down below

and that gives a different perspective a

different view of things and also

explains a couple things more in depth

things that we aren't able to do in the

video so i definitely recommend going to

check that out

as it is hope you enjoyed this and we

will catch you in the next one

you