Why Use AC Instead of DC at Home??

Summary

The video script presents a historical and technical discourse on the use of alternating current (AC) versus direct current (DC) in powering homes. It recounts the famous rivalry between Nikola Tesla, an advocate for AC, and Thomas Edison, a proponent of DC. Despite Edison's attempts to demonstrate AC's dangers, Tesla's AC system prevailed due to its advantages in power transmission. The script explains that AC allows for voltage transformation using transformers, enabling more efficient power distribution over long distances with less power loss. It also humorously highlights Edison's unethical marketing tactics, including public electrocutions, to discredit AC. The video concludes with a reminder of the importance of ethical behavior in business and a giveaway of electronic tools and components, provided by CircuitSpecialists, to support viewers in their electronics endeavors.

Takeaways

• 🏠 **Home Power Source**: AC is used to power homes because most household devices require DC, which is obtained by rectifying AC.
• ⚡ **AC vs. DC Danger**: AC is considered more dangerous than DC at the same voltage level, but higher voltage DC can be equally or more dangerous.
• 💡 **Historical Context**: The preference for AC over DC in power distribution is rooted in the 'War of the Currents', where Nikola Tesla's AC system won out over Thomas Edison's DC system.
• 🐘 **Edison's Tactics**: Thomas Edison tried to discredit AC by demonstrating its dangers through public electrocutions of animals, even inventing the electric chair using AC.
• 🔌 **Device Compatibility**: Despite the preference for AC in power transmission, most home devices and appliances, like light bulbs and electric motors, operate on rectified DC.
• 🛠️ **Motor Lifespan**: Brushless AC motors tend to last longer than brushed DC motors due to reduced wear and tear from brushes.
• 🌐 **Transmission Efficiency**: AC's main advantage is in long-distance power transmission, where it can be stepped up and down with transformers, reducing power loss over lines.
• 🔥 **DC Limitations**: Edison's DC system was limited by the need for thick wires to handle high currents, leading to greater power loss and limited transmission distances.
• 💡 **Incandescent Lights**: Early uses of electricity, like incandescent lighting, did not differentiate between AC and DC, but the rise of electric motors influenced the preference for AC.
• 🤝 **Tesla's Innovation**: Nikola Tesla's improvements to Edison's DC system were not rewarded, leading to Tesla's departure and the development of a more efficient AC system.
• 🎁 **Giveaway**: The speaker is giving away tools and components, including multimeters and lab power supplies, as a thank you to CircuitSpecialists and to encourage viewers to start in electronics.

Q & A

Why is AC power used to power homes instead of DC?

AC power is used because it can be transmitted over long distances with less loss and is easier to transform to different voltages using transformers. This makes it more suitable for power distribution on a large scale.

Is AC power inherently more dangerous than DC power?

AC can be more dangerous at the same voltage levels due to its oscillating nature which can cause muscles to contract and prevent letting go. However, the danger also depends on the current and the conditions of use, and high voltage DC can be equally or more dangerous.

Why did Nikola Tesla win the 'War of the Currents' over Thomas Edison?

Nikola Tesla won because his AC power system was more efficient for long-distance transmission and could utilize transformers to step up and step down voltages, making it more practical for widespread use.

What was Thomas Edison's approach to discredit AC power?

Thomas Edison tried to demonstrate the dangerous nature of AC power by electrocuting animals publicly and promoting the idea that AC was deadly.

How do modern household devices typically use AC power?

Most household devices require DC power and thus have rectifiers that convert the AC power from the wall to DC power that the device can use.

Why did Edison's DC distribution system fail to be as effective as AC for power transmission?

Edison's DC system was limited by the voltage it could use, leading to high currents and significant power loss over transmission lines due to the wires' resistance. It was also unable to efficiently change voltage levels without converting to AC first.

What is the advantage of using transformers with AC power?

Transformers allow AC voltage to be stepped up for efficient transmission over long distances and then stepped down for safe use at the point of use. This reduces power loss and makes the distribution of electricity more practical.

Why are electric motors in home appliances often designed to run on AC rather than DC?

AC motors, especially brushless types, can be more durable and require less maintenance than their DC counterparts. They do not have brushes that wear out over time, leading to a longer lifespan.

What is the main reason for the higher efficiency of AC power transmission over long distances?

By increasing the voltage for transmission, the current can be reduced, which significantly lowers the power loss due to the resistance of the transmission lines (since power loss is proportional to the square of the current).

Why did Tesla leave working for Thomas Edison?

Tesla left Edison after Edison refused to pay him the $50,000 he had promised for improvements to the DC system, dismissing the promise as a joke.

What is the moral lesson from the historical conflict between Edison and Tesla?

The moral is not to let personal rivalry or unethical tactics overshadow the pursuit of innovation and efficiency. It also highlights the importance of fair business practices and respect for one's colleagues and employees.

Outlines

00:00

🔌 The AC vs. DC Debate and Tesla's Victory

The first paragraph discusses the historical rivalry between AC and DC power, highlighting Nikola Tesla's triumph over Thomas Edison. It explains that despite AC being potentially more dangerous, it won out due to its advantages in power transmission. The paragraph also touches on Edison's unethical tactics to discredit AC and Tesla's innovations that led to more efficient power distribution using transformers to step up and step down voltage for long-distance transmission.

05:07

🛠️ Demonstrating AC Power Transmission with Transformers

The second paragraph presents a practical demonstration of AC power transmission using transformers. It illustrates the process of stepping up voltage for transmission and stepping it down at the point of use. Despite an initial failed experiment with unsuitable transformers, the video shows that AC can transmit power over a line without burning it up, unlike DC. The summary emphasizes the efficiency gains from using high voltage AC for transmission and the impracticality of achieving similar results with Edison's DC system.

10:12

🎁 Giveaway and Closing Remarks

The final paragraph announces a giveaway sponsored by CircuitSpecialists, offering tools and components to patrons and viewers. It also includes a moral lesson about the importance of fair business practices, alluded to through Edison's conduct. The host, Unibrow, provides a link to a Google Form for viewers to enter the giveaway and concludes the video.

Keywords

💡AC (Alternating Current)

AC refers to an electric current that periodically reverses direction. It is the type of current commonly used to power homes and is the subject of the historical 'War of the Currents' between Tesla and Edison. In the video, it is discussed how AC won over DC for power distribution due to its ability to be transformed for long-distance transmission with less loss, despite the efforts of Edison to discredit it.

💡DC (Direct Current)

DC is an electric current that flows in a single, direct direction. It was the type of current advocated by Thomas Edison and is contrasted with AC in the video. Edison's DC system was limited by the inability to efficiently transmit power over long distances without significant power loss, a limitation that AC overcame with the use of transformers.

💡Nikola Tesla

Nikola Tesla was a Serbian-American inventor, electrical engineer, and physicist known for his work on alternating current systems. In the video, Tesla is portrayed as the winner of the 'War of the Currents', with his AC system being favored for its ability to transmit power efficiently over long distances, a concept demonstrated through an experiment in the video.

💡Thomas Edison

Thomas Edison was an American inventor and businessman known for his development of the first commercially viable incandescent light bulb and the phonograph. In the video, Edison is depicted as a proponent of DC power and is criticized for his unethical attempts to discredit AC power, including public electrocutions.

💡Transformers

Transformers are electrical devices that change the voltage of an alternating current. They are crucial for the efficient transmission of AC power over long distances. In the video, the use of transformers to step up and step down voltage is demonstrated, showing how AC power can be made suitable for both transmission and home use.

💡Rectification

Rectification is the process of converting alternating current (AC) to direct current (DC). The video mentions that most home devices require rectification before they can use the power, highlighting the prevalence of DC in electronic devices despite the use of AC for power distribution.

💡Electric Motors

Electric motors are machines that convert electrical energy into mechanical energy. The video discusses how electric motors, such as those in appliances like meat grinders or fans, can be designed to run on either AC or DC. It also touches on the longevity of brushless AC motors compared to brushed DC motors.

💡Transmission Lines

Transmission lines are the infrastructure used to transmit electrical power from its point of generation to its point of use. The video explains how AC's ability to be transformed for high-voltage transmission allows for more efficient power delivery over these lines, overcoming the limitations of Edison's low-voltage DC system.

💡Power Loss

Power loss refers to the decrease in electrical power as it is transmitted over a distance. The video illustrates how power loss is minimized in AC systems due to the ability to increase voltage and decrease current, reducing the resistive losses in transmission lines.

💡Incandescent Lights

Incandescent lights are a type of lighting technology that produces light by heating a filament. The video mentions that these lights were the primary use of electricity at the time of the 'War of the Currents' and that they do not differentiate between AC and DC power.

💡Safety Concerns

Safety concerns are the worries about the potential harm that can come from using a particular technology. In the video, Edison's campaign against AC power is highlighted, focusing on the dangers of high-voltage AC, despite the fact that high-voltage DC can be equally or more dangerous. The video also demonstrates that while AC can be dangerous, proper handling and understanding can mitigate risks.

Highlights

AC power is used in homes due to historical reasons and advantages in power transmission.

AC is considered more dangerous than DC at the same voltage level, but higher voltage DC can be equally or more dangerous.

Most home devices convert AC to DC before use, highlighting the prevalence of DC in electronic devices.

Nikola Tesla's AC system won the 'War of the Currents' over Thomas Edison's DC system due to its advantages in power transmission.

Thomas Edison's attempts to discredit AC by public electrocutions of animals and the invention of the electric chair failed to deter AC's adoption.

AC power can be transmitted over long distances with less loss due to the ability to transform voltage levels.

Edison's DC system was limited by the need for thick wires to handle high currents, which resulted in significant power loss over distance.

Nikola Tesla improved upon Edison's DC system but was not compensated as promised, leading to Tesla's departure and development of the AC system.

Transformers allow for efficient AC transmission by stepping up voltage for long-distance travel and stepping down for end-use.

The experiment demonstrates that AC can be transmitted with less power loss compared to DC, even with suboptimal transformers.

High voltage transmission reduces current, which in turn reduces power loss in wires due to the inverse relationship between voltage and current.

The practical application of high voltage transmission in real life involves converting voltage to tens or hundreds of kilovolts for efficiency.

Thomas Edison's resistance to change and negative campaigning against AC power ultimately did not succeed in halting its widespread adoption.

The video concludes with a moral lesson on the importance of not letting personal biases interfere with technological progress.

CircuitSpecialists is acknowledged for providing tools and components, and a giveaway is announced for patrons and viewers.

The giveaway includes five LCR meters and four lab power supplies, with an entry process outlined in the video description.

Transcripts

Hi. Why do we ever use AC to power homes instead of DC?

Haven't I showed you that AC is typically more dangerous than DC?

[Painful Gurgle]

Can we run everything on DC?

Yes! In fact pretty much every device at home has to rectify AC into DC

first before it can use it so why? Why am I angry?

The reason is elementary. Once there was a fight between a guy named Nikola Tesla being AC and Thomas Edison

being DC and Tesla won the contract on his employer Westinghouse company to provide power with AC

no matter how hard Thomas Edison tried to expose the dangerous nature of AC by

electrocuting dogs and elephants in public.

Wow

Now I remember why I'm angry; this Edison guy was an animal! He even invented the electric chair to execute with AC

--not because it was a cleaner or better way to execute--because he wanted to deface AC by forever associating it with death.

Nikola Tesla very rightfully won this battle.

Yes, AC can be more dangerous than the same level DC but a higher level DC can be as dangerous

if not more and just because something is dangerous

we don't stop using them like for example if you live in a high-rise

you are not in a constant risk of jumping off the window. But is there an advantage of using AC?

I mean, back then all they wanted was light using incandescent lights and those don't care about AC or DC.

Here I'm running a regular light bulb on AC as usual

and here I

S**t

S**t

I killed it.

Don't short s**t.

Anyways with this I'm converting the AC into DC using

It's a single diode, but it will do and if I measure the voltage at the output

F**k

S**t

Holy f**k the capacitor

Ah f**k

F**king piece of s**t

Anyways i'm reading around

170 volt DC and although it's still quite dangerous

I can still touch it and it's not as remotely as painful as touching the 120 volt AC

and the lightbulb

Runs on it just fine

And it's even a little brighter because it's 170 volt continues

Beside the lights the electric motors were becoming more popular in home

Appliances like meat grinders or fans and such, but even those could be made into brushless

AC or brushed DC for example, of course a brushless AC motor like this one that I took from an old

microwave oven can last much longer than a brushed DC...

(S***,F***)

Loose wires, avoid them anyways brushes in DC brushed motors wear out eventually

And that's why AC motors can last longer, but beside that fact there doesn't seem to be much preference between AC and DC

But the real advantage of AC is not at home

It's before electricity even gets to home in transmission lines

And that's why Edison's DC power distribution system eventually died away, here

I made a transmission line using thin wires and using my supply

I'll try to place 10 volts across my 1 ohm load for 10 amps of current

And I'm measuring the voltage across my load. Let's try it

See the voltage is like

seven and a half and you see my

Transmission line is starting to smoke and heat up and the voltage continues to drop see the line resistance is so much that the voltage

Across the load doesn't even get to ten volts

It's at seven volts for seven amps through the load and because of the high resistance. It's heating up so much

Similarly because Edison was passing low voltage across the transmission lines a ton of current was passing through the lines

And there is a limitation to how thick you can make the wires before they break under their own weight or become too expensive

Huge currents through the resistance of the wire would result in large voltage drops over longer distances

And that's why Edison's system could only transmit power to around a mile or two from the power source

Otherwise the power loss would be so much over the lines

That would cause huge inefficiency, of course Edison was aware of his s**tty system

So he decided to let one of his genius employees to take care of the problem, who was our beloved Nikola Tesla

He was working for Edison at the time. according to Tesla Edison promised him

$50,000 which was a lot of money back then, if Tesla was able to make great improvements to Edison's DC system

Which Tesla did in a few months and when he went to Edison to ask for the money?

He said "Haha. I was joking obviously you're not aware of our

American humor," which Tesla said "F*** you, I quit !!!"

Later Tesla came up with his genius system and developed it for Westinghouse company

What he did was to transmit power much smarter. He used AC so he could change the voltage level using transformers, here

I'll use my auto transformer to generate 10 volt AC which would result in 10 amp AC through my 1 ohm load

But before I send it through the transmission line, first

I'll step the voltage up using my microwave transformer

and then I would step the voltage down after the line if I had a transformer

Well, guess I can borrow the one from our microwave

F**k. They're using tamper proof screws to stop me

What they don't know is that nothing can stop me. They are just postponing the inevitable

There we are...

I'll just take a picture of the wiring before I pull it out. I don't want to blow it up later

There we are

Ok, now we have both transformers connected. Let's do some voltage measurements before I connect the load. At the input

We have close to 10 volts so that's good. On the transmission line

We get around 190-200 volts. And at the output

Again we have close to 10 volts so that's pretty good. Now, let's connect a load

Ok. And the voltage across the load is

1.6 volts? That's garbage. What happened? The transmission line voltage

118 volts? Everything dropped

This is worse than the DC system. What's going on Tesla? Let's measure the transformer secondary winding resistance

Around hundred ohms. No wonder

There's too much drop over the large resistance of the secondary, so these transformers are not made for this purpose

That was a bad example. It doesn't matter. I'm gonna transmit power. No matter what

2 volts. 3 volts

4. 5. 6. 7

8. 9

And 10 volts across the load. We did it

And our transmission line is not burning so that's always a plus

Nothing is exploding. What is the transmission line voltage now?

820 volts!!! Well anyways, although

This is a pretty bad example, you can see that

I'm transmitting more power than the DC system

But my transmission lines are not burning. So, that's sort of a success?

See in this system

I can transmit a lot of power in this case around hundred watts without having to thicken the transmission line wires

And if the Transformers were better the efficiency would be higher, too

In fact, in this system, the higher you convert the voltage to, the easier it is to transmit power over greater

distances, with some limitations, of course. That's why in real life, they convert it to 10 kilovolt or hundred kilovolts

Why? Because in transformers, the input and output power is

ideally the same, although not really, because there's always some power loss as you saw, and power is voltage times current

So, for example, if I increase the voltage by

20 times, in order to have the same power, the current has to drop by 20 times at the output of the

transformer and over the transmission lines. And because the power through a resistor is equal to resistance times current squared

The power would be 400 times less wasted on f**king wires

F**k

And with high voltage comes great responsibility

The transmission lines have to be placed far enough so no arcing happens

There is no easy way to do the same thing with Edison's stupid

DC system. In order to change the voltage, you would have to convert DC to AC,

increase the voltage, and then convert the AC back to DC, and lose a lot of power in the process

Edison still couldn't see this. All he saw was that his company was losing the contract of his life to power the world

So all he did was to grab the fact that

Tesla's system was running on super high voltage, like 10 kilovolt or 100 kilovolt, and say that it's super dangerous to people

by electrocuting animals with 10 kilovolt in public

Thomas Edison. He contributed a lot to science and technology what he was also an a$$hole

businessman, and that bit him in the lower back area

the moral of the story, don't be an a$$hole

GIVEAWAY TIME!!!

You know, CircuitSpecialists has been quite nice to me providing all my basic tools and components and everything

And I really hope you find what you need In their website too

And, I'm quite happy with the multimeter they sent me, which is an LCR meter. It measures inductance, capacitance

resistance, voltage, current, and a bunch of more stuff. So thanks to CircuitSpecialists

I'm gonna give away five of these to my patrons at patreon.com

and you the viewers. Also, if you want to start electronics you would need a lab power supply

And I'll give away four of those too. As usual, my patrons are automatically in the draw. For everyone else

please follow the link to the Google Form in video description and let me know which one you need and I'll draw your name

and that's it. Unibrow out