# Capacitor Pyramids as Energy Source. Why or why not? **URL:** \ **Category:** Factual Questions\ **Created:** [July 18, 2006, 3:57pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029 "2006-07-18T15:57:40Z")\ **Posts on this page:** 5\ **Page:** 3
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [November 23, 2017, 2:37pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/41 "2017-11-23T14:37:55Z")
> [@engineer\_comp\_geek](#): > > When I was in college (back in the days of dinosaurs), they would take old electronics and would leave them in a room on the top floor of the engineering building for us EE students to tinker with and to use in our projects. I got a capacitor about that big in diameter and about twice as tall out of that junk pile. We had of course learned how capacitors store energy and how you can discharge them, so I charged that capacitor up and shorted it with a screwdriver just to see what would happen in the real world. It arc-welded the screwdriver to the capacitor terminals, and blew the tip off of the screwdriver while it was at it. > > It gave me a healthy respect for larger capacitors. 🙂 Not remotely on the same scale, but back when they were a thing (are they still a thing?) I had removed the exposed film from a disposable camera (to send of for normal processing–I never sent the whole camera off) and out of curiosity started disassembling the rest of it to examine. I accidentally found the two leads that discharged the capacitor for the flash. No physical damage done, but it was a bit of a sudden reminder that I wasn’t thinking things through enough. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [November 23, 2017, 3:19pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/42 "2017-11-23T15:19:05Z")
> [@engineer\_comp\_geek](#): > > When I was in college (back in the days of dinosaurs), they would take old electronics and would leave them in a room on the top floor of the engineering building for us EE students to tinker with and to use in our projects. I got a capacitor about that big in diameter and about twice as tall out of that junk pile. We had of course learned how capacitors store energy and how you can discharge them, so I charged that capacitor up and shorted it with a screwdriver just to see what would happen in the real world. It arc-welded the screwdriver to the capacitor terminals, and blew the tip off of the screwdriver while it was at it. > > It gave me a healthy respect for larger capacitors. 🙂 This keeps the number of EE’s down and the wages of those that survive up? … that’s one mean labor union … yeesh … “Here’s a big capacitor for you to play with.” … ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [November 23, 2017, 4:47pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/43 "2017-11-23T16:47:49Z")
A CRT is a very high-quality capacitor. If you turn off an operating color TV, and immediately remove the HV lead, the tube can store a 25KV charge for many months in dry weather. I used to work in a TV repair shop, and always made a point of discharging any CRT sitting on the shelf before touching it. It was possible to draw a 1/2” spark from one that had been sitting for awhile. ---
**Author:** ![Khendrask](https://avatars.discourse-cdn.com/v4/letter/k/3e96dc/32.png) [@Khendrask](https://boards.straightdope.com/u/Khendrask)\ **Post date:** [November 27, 2017, 10:49am UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/44 "2017-11-27T10:49:46Z")
> [@Lickety\_Split](#): > > But are you sure those systems are capacitors and not transformers? I have never heard of a true capacitor outside of electronics. Maybe you could throw me a link or a source? Thanks! I don’t know what you thing of a “True Capacitor”. They are indeed used in automated switched banks for power factor correction, and can be the size of small cars even on an relatively low voltage (24,900 V) sub-station. [Here’s a catalog since you want links](http://www.eaton.com/Eaton/ProductsServices/Electrical/ProductsandServices/PowerQualityandMonitoring/PowerFactorCorrection/index.htm). We also use capacitor voltage dividers here on our high voltage test sets. Those capacitors stand about 12 feet tall, and 3 feet around. [Here’s a catalog since you want links.](http://www.rossengineeringcorp.com/products/measurement/hv-voltage-dividers.html) ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [November 27, 2017, 12:46pm UTC](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029/45 "2017-11-27T12:46:00Z")
> [@Lickety\_Split](#): > > But are you sure those systems are capacitors and not transformers? I have never heard of a true capacitor outside of electronics. Maybe you could throw me a link or a source? Thanks! How would a transformer fulfill the power-factor correction functionality of a capacitor? A capacitor stores energy when the line is at peak voltage, whereas ISTM that a transformer would behave like a simple inductor, storing energy when the line is at peak current. [Previous page](https://boards.straightdope.com/t/capacitor-pyramids-as-energy-source-why-or-why-not/365029.md?page=2)