# Capacitor question **URL:** \ **Category:** Factual Questions\ **Created:** [August 28, 2022, 9:28pm UTC](https://boards.straightdope.com/t/capacitor-question/970486 "2022-08-28T21:28:48Z")\ **Posts on this page:** 8\ **Page:** 2
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [August 31, 2022, 11:38am UTC](https://boards.straightdope.com/t/capacitor-question/970486/21 "2022-08-31T11:38:42Z")
Thank you for interesting information! Well, at least I know THE single most important thing about electricity that I need to know. CALL AN ELECTRICIAN! LOL ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [August 31, 2022, 12:09pm UTC](https://boards.straightdope.com/t/capacitor-question/970486/22 "2022-08-31T12:09:45Z")
My analogy was meant merely to mean that those who talk up the danger of capacitors are more often that not people who have no practical experience of the subject, really, but are nonetheless happy to repeat dubious but thrilling Tall Tales of far off danger. > [@am77494](#): > > Yes you are right. Old CRT TVs and some other electronics did have capacitors that would give you a nasty shock. But nowadays most electronics do not use have that kind of voltages. > > Besides, electrolytic capacitors like the ones in OP are like very small rechargeable batteries and they do not go to high voltages. Very unlikely to get a shock from an electrolytic capacitor. > > The point about retaining charge after plugging off is valid too but again not with this kind of capacitor. Electrolytic capacitors have a leakage resistance that discharges them fairly quickly Now you are underplaying the position. Most modern electronics have a power supply that contains a large electrolytic capacitor which (when charged) will typically be at 150v DC in the USA and 330V in places with 240V mains. Needless to say, that is enough to bite you pretty hard. I would expect the OP’s device to have this. And you can definitely get a shock off an electrolytic capacitor after plugging out. Yes electrolytics leak charge but no so fast that you can’t unplug, open the case, and get a shock. Ask me how I know! ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [August 31, 2022, 12:12pm UTC](https://boards.straightdope.com/t/capacitor-question/970486/23 "2022-08-31T12:12:30Z")
> [@pjd](#): > > “Landlubber” does not seem to be quite as offensive as the definition > of “Lubber” suggests … Well, “useless longshorer” is still pretty judgmental and I can see one taking offense to that. It’s interesting, because, like **Jasmine** , I did think “land-lubber” was a corruption of “land-lover” (“b” ↔ “v” phonemic changes are common in languages) only to discover that “lubber” is a word in its own right which forms the second half of the compound “landlubber.” ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [August 31, 2022, 12:14pm UTC](https://boards.straightdope.com/t/capacitor-question/970486/24 "2022-08-31T12:14:42Z")
It is without question a judgmental term. It is a term seafarers use judgmentally about people who don’t know about matters maritime. I am a landlubber. ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [August 31, 2022, 12:21pm UTC](https://boards.straightdope.com/t/capacitor-question/970486/25 "2022-08-31T12:21:58Z")
> [@Princhester](#): > > And you can definitely get a shock off an electrolytic capacitor after plugging out. This leads me to what I think is my last question. How long do they hold a charge? I’m thinking it varies with the type of capacitor and the device in which it is being used. > [@am77494](#): > > Old CRT TVs and some other electronics did have capacitors that would give you a nasty shock. Is the high voltage why CRT TVs were all crackly and full of static electricity if you got near the screen? I remember when I was little (about 8), I moved up close to the screen, and my hair was suddenly plastered to the screen. It scared the heck out of me because I had seen part of the movie Poltergeist, specifically the little blond girl and the TV. LOL ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [August 31, 2022, 12:27pm UTC](https://boards.straightdope.com/t/capacitor-question/970486/26 "2022-08-31T12:27:37Z")
> [@Jasmine](#): > > This leads me to what I think is my last question. How long do they hold a charge? I’m thinking it varies with the type of capacitor and the device in which it is being used. There is no single answer. Most well designed devices _should_ have a bleed resistor across any dangerously high voltage capacitors but some don’t. Capacitors vary tremendously in capacity (ie by several orders of magnitude), and in their leakage current. So how long they take to leak down to a safe voltage cannot be boiled down to a single answer. Really, if you are going to be playing with this stuff you should (a) understand how to recognise the high voltage capacitors in a given device and (b) know how to discharge them. It’s not hard to learn. > [@Jasmine](#): > > Is the high voltage why CRT TVs were all crackly and full of static electricity if you got near the screen? Yes. They typically used the entire CRT envelope as a great big high voltage capacitor. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [August 31, 2022, 2:22pm UTC](https://boards.straightdope.com/t/capacitor-question/970486/27 "2022-08-31T14:22:30Z")
> [@Jasmine](#): > > I remember when I was little (about 8), I moved up close to the screen, and my hair was suddenly plastered to the screen. It scared the heck out of me because I had seen part of the movie Poltergeist, specifically the little blond girl and the TV. LOL You mean like this 🙂 [![](https://www.lehigh.edu/~amb4/wbi/aglancy/5B1010.jpg) ](https://www.lehigh.edu/~amb4/wbi/aglancy/5B1010.jpg) Well thats not a capacitor but a Van-de-Graff generator which is close. And thank you for giving me this idea : I will try to use your idea with my teenage daughter and maybe she will get interested in this stuff 🙂 ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [August 31, 2022, 2:53pm UTC](https://boards.straightdope.com/t/capacitor-question/970486/28 "2022-08-31T14:53:54Z")
> [@am77494](#): > > I will try to use your idea with my teenage daughter and maybe she will get interested in this stuff 🙂 Or maybe she’ll get really annoyed that her hair is a complete mess. LOL [Previous page](https://boards.straightdope.com/t/capacitor-question/970486.md?page=1)