Where to buy DIY or home made capacitor book(s)?

[HVuser]

After looking at the prices of MMC and used high voltage capacitors I feel it will be more affordable to make my own capacitors. I have seen videos online in the past on how to build HV capacitors although I want to buy a book. Normally I would turned to Lindsay technical books but that company does not have many books anymore. Does anyone know a good book on how to build DIY or home made capacitors?

[MRMILSTAR]

Capacitors for Tesla coil primary circuits are usually the most expensive and difficult to obtain part of a Tesla coil. I haven't attempted to make any myself but I can report that many have tried and seldom had success for any length of time. They usually fail after a short period. Unfortunately I don't know of any inexpensive methods for obtaining a reliable Tesla coil capacitor bank. I am not aware of any books either.

[HVuser]

I feel we have to have some modern books on the subject as I have found many books on what capacitors are, how to use them, and theory of operation. I know it is possible that companies could claim manufacturing of capacitors as proprietary information. I have seen home made capacitors fail on YouTube causing all sort of problems. I appreciate the information.  I will have to give it more thought and weigh the benefits/drawbacks.

[davekni]

My experience with home-made HV capacitors comes down to two key issues.  One is creepage - arcs forming along insulation surfaces around from one electrode to the other.  Second is more difficult, corona in any tiny air space eventually breaks down neighboring plastic insulation.

Both issues could be mitigated by running the capacitor in an oil bath (with proper trapped-air removal).  Too much trouble and mess for me.

[HVuser]

You bring up some good points. I will still try home made capacitors if I can find some Mylar or Melinex film.  I appreciate the information.

[davekni]

Mylar and Melinex are brand names for polyester.  It is a great dielectric for DC use, but too lossy for AC.  MMCs are almost always made with PP (polypropylene) dielectric caps, with very-low dielectric loss.  Polyethylene film is much easier to buy and also low-loss, although temperature is even more limited than for PP.

[Twospoons]

Note: for high voltage its better to use several thin layers of dielectric than one thick one. This because if there's a defect in the film at one point it will most likely not be next to a defect in the adjacent layer, so you are far less likely to have a defect driven failure of the capacitor.
Its also easier to roll.

Years ago I bought a big roll of kraft paper, for a big paper-in-oil capacitor. But like so many ideas, it got shelved. I have a garage full of half completed projects.

[huntergroundmind]

I have mixed feelings about making DIY capacitors. I number of them, and concluded that it is actually hard to do an realible capacitor. Long ago I did "sandwitch" style capacitors for my first Tesla coils. Because of lack of impregnation they failed due to corona eating out garden PVC foil. After I noticed that I applied edible oil between aluminium, and dielectric foils during assembly, and it worked for some time of operation. More recently I made capacitors from... old capactitors. I rewound old windings from dead pfc capacitor to form smaller capacitors, and connected them in series to get demanded voltage rating. Later I vacuum impregnated them in oil. It worked for some time In primary circuit of some sort of tesla coil, and It failed after some time ( most probably due to bridging of impurities in oil in one capacitor, after that sequential failure of other caps happened ).  Microwave oven capacitors also are good source of ready made  dielectric material(mylar and paper), and aluminium foil stacked together. I made some capacitors for CW stack dry, wax impregnated) by rewinding them, and "converted" one MOC to low inductance one by adding more outgoing foils on lenght of winding, and connecting them in parallel. Then vacuum impregnated it in transformer oil.
Cleanliness is a key. Any dirt, especially harder kinds (such as sand, or metal fillings for worst) that fall into capacitor during winding of foil cause problems (punctures, and being sharp points engancing electric field if conductive). Also better filter your oil before you fill container of capacitor.

[Robert3z]

If you want to do it, there's a reprint of a 1902 book called "Induction Coils" by Norman Hugh Schneider, available from Franklin Classics (UK). You can find it on Amazon. There are chapters on homemade everything in it, including an adjustable primary cap that looks pretty dodgy (but cool)!
 If you wanted to do a period coil (aka 1890's) that's 100% real it's your reference.
The ads for the book company's other offerings in the back are very entertaining too.
It also includes a chapter on "experiments" or making cool glowing things. I am very happy with the purchase.