[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: oil dielectric

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Xyme3-at-aol-dot-com>

 Sorry i sent the last EM by accident, this is the conclusion, the other half 
being discussed in the last letter. 

<<  The oil actually keeps the coil cool by damping molecular

> movement.

    The thermal effect is by being heated by hot spots
    (core eddy currents, coil resistance losses), then flowing,
    by natural convection, or, less commonly, pumped
    circulation, to a cooler spot where it can dump heat.
    Sometimes the cool spot is aided by heat sinks ('fins').
    cf any text on transformer design.
I think you are correct here also, fins would help
dump heat. 

> The way I wound the coil was to wind it on a 3.5" OD
> PVC pipe and then slide a 4.5" OD PVC pipe over it and seal

    This makes me nervous.

> both ends.  I left a quarter inch hole in the top plug and used

> something like a turkey baster to fill the coil with oil. When I

> was done, I sealed the small hole.

    I say nervous because a sealed container, can, if heated,
    even by a fault, 'rapidly disassemble':  Explode.
    Unlikely, probably, here, but possible.  (Power
    transformers can and have exploded, when not vented.)
  I think there are some relief valves that contain the additional material 
pushed out by heating. When the oil cools the valve allows the oil to flow 
back into the container. 
PS Thanks for the comments, you have pointed out some mistakes that could 
easily be made by an amature, like me.