Plastic Plate Capacitors

We have been featuring some home made capacitors this week, and [Mike] wrote in to share his with us. While rolled capacitors are nice, they can be somewhat difficult to construct and grow to unwieldy sizes as capacitance and voltages increase. His solution is to stack the layers up using plastic plates.

In this forum post he explains that using disposable plastic plates and tinfoil you’re able to quickly make a capacitor, that for him was valued at around 12.2nF, using eleven layers . Applying pressure to the stack capacitance grew to about 14nF, though he is having a bit of trouble holding it with just glue.

Testing was conducted with high voltages charging the capacitor up, then its leads were shorted for a nice spark and a good pop. Definitely fun for the next family cook out, though we don’t know how some left over potato salad goo would effect the end results.


  1. Bill says:

    Seems like DIY capacitors should be a right of passage project (among others) for EE students.

    I remember building HV beer-bottle caps in High School.

  2. Homer says:

    I remember making capacitors with plastic drinking cups in Physics II in high school. Fun times: charge it up, throw it at a friend who isn’t in Physics (or one that is, either was hilarious)

  3. aztraph says:

    Ok, Kudos for making capacitors. but those are a couple of microwave transformers in the background there, I pray you know what you are doing. 2,000 volts at 5 to 8 amps kills quickly.

  4. Ed says:

    Capacitor fever at hack-a-day.
    Next week — knit your own diodes

  5. Jack says:

    I also did a double take with the series MOTs. He has them set apart with the box, so I think he has an idea what he is doing.

  6. jeditalian says:

    tater salad goo would convert it into an electrolytic capacitor, which would be leaking and therefore its capacity diminished.

  7. danielmiester says:

    I can’t remember where I saw the pic. but At one point during the initial development and utilization of radio, they were building transmitters with HUGE HALLS and filling those halls with parallel plates to create the needed capacitance at the many kV they were running at.
    This pic showed a man standing at the base of one of these plates, a sheet >20ft wide and 80ft tall!

  8. strider_mt2k says:

    hehe potato…potato POTATO SALAD…OF COURSE!!!!

    (runs from the room)

  9. holly_smoke says:

    The capacitor was roughly 12.2nF

  10. holly_smoke says:

    “though he is having a bit of trouble holding it with just glue.”

    Clamp the plates, like if you are making a laminate.

  11. Mousefinder General says:

    Lookie here for an absolutely fascinating account of the construction of a radio in a WWII Japanese POW camp:

    The prisoners manufactured capacitors, resistors and an AC-DC rectifier all from things they could steal from around the camp!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


Get every new post delivered to your Inbox.

Join 96,380 other followers