above: first can crushing setup

Wow. I had time today to play with my version of a can crusher. Not all the pictures
made sense so I only have a few posted.

First off, my can crusher is different from the others I have seen. Everybody else
has film/foil high voltage energy discharge caps. I just have a case of electrolytic
invert caps. This limits the voltage I can run at as well as the discharge times I
can reach. Film/foil caps are much "faster".

In any case, I tried banks of 8 and 16 caps charged from 650V (1390J) to 16
caps charged to 1300V (2780J). This is far below the several to 10 or so kV
others use with film/foil caps. 

1390J discharges only wrinkled the can in a funny way. This also caused my solenoid
which was about 4 to 5 turns of 1/4" OD soft copper tubing to crush itself. Somehow
my coil tried to crush itself everytime I operated it. After three shots the center
turn were crushed completely flat. I have this on videotape as well.

2780J discharges were not only extremely loud, but quite damaging to my coil. I
insulated the layers from each other with three strips of fish paper woven back and
forth to say I tried. To fire the whole circuit I used a medium sized 20A DPDT
contactor. I bend the NC terminals to leave alarger air gap and wired the C
terminals to each other. This doubled the air gap between the NO terminals which I
connected to the cap bank and solenoid. In the pictures you can see weird stuff like
a 400A shunt and red hospital grade outlet. I used them to join the 10AWG solid wire
because they were convenient.


above: 2780J 1300V setup

For the 1300V tests I put the contactor in a thick cardboard box. This blew
open and shot sparks when it closed. I have this on tape as well. With 1390J it
made a huge smoke cloud and welded closed. 

I wish to up the ante and try a 2.6kV bank in the next few days to see what happens.
I will also make a tape wound coil with copper strip and cardboard. I want the
magnemotive force to destroy the can, not my coil.


above: only my coil was getting beat up. It was pretty and completely round 
at first


above: you can see that much of the tubing is now concave

I will post pictures and results as they happen.


02-25-2000 02-21-2000