What does a capacitor do?

In this video, I'm connecting a circuit with an LED and a resistor. To show you exactly what a capacitor does.

When I connect the plus and the minus from the battery, the LED lights up.

Nothing magical here.

And in the exact moment when I disconnect the power, the LED turns off.

Next, I'm connecting a capacitor.

I connect it across the LED and the resistor.

Then I reconnect the power, and the LED lights up again.

But take a look at what happens when I disconnect the power:

The LED stays on!

And after a few seconds, you can see it fading out.

This is because the capacitor is kinda like a tiny battery.

When I connected the power, it charged up.

Then when I disconnected the power, it started using its stored energy to keep the LED on.

This is very useful to make for example a time delay in a circuit.

Or to make filters.

If you have no idea what a filter is, here's a simple one:

Imagine a terrible battery that for some reasons keeps turning the voltage on and off every second.

Without the capacitor, the LED would be blinking.

But with the capacitor, you'll filter out the OFF periods and get an LED that is always on.

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Hope to see you there!

Thanks for watching!

[lindascoon]

Thank you for getting right to the point. It's amazing how your short video explains this better than some long videos here on YouTube

[Montee]

Finally a video that doesn't have to do something complicated to explain it and just gets straight to the point. Thank you.

[murraymisha]

A great way to demonstrate how a capacitor works

[yoko]

My teacher sent us this link thorough online school

[luke]

Thanks. I connected a LED light to my alarm clock to see the analog tuner at night but it is never a constant light since it turns on and off based on the sound. Looks like a capacitor is what I need and I found one from an old rc remote.

[YD-uqfi]

This video could have saved me a lot of time 30 years ago. kids today don't know how good they have it.

[vangelova]

This is perfect! I made it myself and it worked right away! Thank you so much for the useful demonstration!

[chuckthesham]

Great explanation, the best I have seen for a capacitor.

[kurddata]

Hey man! I consider you as my primary teacher :) thanks

[knightridersofgreece]

help me on this please!what type of capacitor do i need to buy in order to give a spotenious fade when i turn off the switch on a 12v 100watt halogen car lamp!

[kakoozaxenyondo]

Simple and brief video. Thanks Professor

[AshishAdhikari]

Wooah, that was a short crash course that was absolutely amazing

[robotboy]

Hi, how can i do this but the other way around.. ??
Basically, i want the led to slowly fade on when power is connected to the circuit ??
must i connect the capacitor in series ??

[AnonyTests]

After doing this do we need to remove the capacitor and discharge it, or did it already get discharged when the led finally turned off?

[stachu]

Thanks for the video! I've been trying to learn some electronics and every other video just explained how it works, without actually telling me WHAT it does haha. And don't get me wrong, I'm into that stuff too, I just wanna learn the basics first and the physics behind it later heh

[mehdijafari]

thank you very much for such great concise explanation

[arftrooper]

This video was so helpful, thank you!

[bekkerthesokuangeldragon]

That is just goddam cool on how it works. I was alway's curious and wondering on how Capacitor's and resister's work and now i do !

[rajaryantiwari]

A question ✋🏻, can we use the LED without the resistor??

[richardworden]

If i have a small solar panel. And the output is 5vdc can i add a cap. At the output to make it move of a stable voltage. . It will charge my phone but i am trying to make it work better with less Fluctuation on the output side.