The Rectifier Circuit

We want to have the inner grid negative and the outer grid grounded. To do this we need only the negative output of the NST. The act of converting AC power to DC is called rectification. Since we want to have one polarity we will need to rectify the output of the NST. There many ways to do this but this is the most simplest, all we need is two diodes. These diodes can be bought online or ripped out of an old microwave. Arrange the diodes as follows:

 
Here is the circuit in real life:

The rectifier circuit is done!

Next: Feedthroughs

The Pump

For a fusor to work you need a vacuum. Having too much air in the chamber where the reaction will happen will slow the ions down and cause no reaction. This is why a vacuum pump is needed. The pump will suck out most of the air in the chamber allowing the little remaining air to ionize and move freely. The pump you will need must be a vacuum pump. Rotary vane vacuum pumps are the best to go for, this is the one I went for -

 http://www.ebay.co.uk/itm/Industrial-Quality-Professional-Vacuum-Pump-50-l-min-/141067535164?pt=UK_BOI_Medical_Lab_Equipment_Lab_Equipment_ET&hash=item20d847c33c

Im sure there are many other vacuum pumps out there that would also work but generally 1/4 Hp, 3 CMF, single stage rotery vane vacuum pumps are the best to go for.

Next: The Rectifier Circuit