Capacitor Discussion from Images Section

[Frank Sanns]

Larry,

You should have seen me fire up the first cap. I started with just one cap and at only 50 volts. Even through 500 mH inductance, the arcs really became quite remarkable by a few hundred volts. I didn't have the guts to do a spark discharge on a fully charged cap.

Don't worry, I will not mix capacitor sizes. It will be enough of a juggling act as it is.

I still am concerned for the plasma impedence in the 15 mtorr range. All the capacitance in the world is not any good if the impeadance is so high that it will current limit the discharge. The question becomes then, what is the pressure of deuterum that will permit a multi megawatt discharge?

Will higher surface area electrodes (i.e. inner grid) give lower impedance?

Frank

[Frank Sanns]

Richard Hester,

Thanks for the advice.

I did not buy these caps specifically for fusor work but rather for other projects such as the laser. Just thought that it might make for an interesting fusor shot. At $50 each, I did not want to pass them up.

I do not usually trust the cases even at the rated voltages and tend to put my caps on some plywood to futher insulated them. For my "big bang" experiment, I was thinking of building an elevated wooden platform on wheels to move my caps around and to keep them high off of the floor. Between them an inch of styrofoam insulation should hold them apart far enough since it is only 4kv per step.

Do you think 1ma is enough current between the caps for equalization? I can't imagine the leakage current to any more than a couple of ua at most.

[3l]

Hi Frank:

The most I've discharged up to this point is 2uf @ 50kv.
5 microns will do nicely.
Impedence is about zero if you glow before you go.
It was soo loud , it sounded about like a 105 howitzer shot.
Ozone was so thick ,I could still smell it on my shirt outside the shop.
Busted one glass window in my shop.
It was about 1kj.
For reference one stick of dynamite is about 10kj.

Careful.... use ear protection..... use discharge dropping resistor
to be safe!

Happy fusoring!
Larry Leins
Fusor Tech

[Richard Hull]

Capacitors are not toys and the blast from them surprising.

Tesla once said..."the energy released in a blast of dynamite is but as the breath of a consumptive compared to that released in capacitive discharge."

Richard Hull