My Finished transformer:

It works ha ha ha :)

 

• Dimensions 12" * 11" * 2.5"
• Weighs about 40 Lbs.
• Insulation rated 120 kv for each leg.
• Estimated time of construction 16 hours.
• Total cost 40 US Dollars
• Special thanks to a friend.
• He shiped it to me for free.


    It doesn't look great but it makes a huge Jacob's ladder at 14.7 kv 247 ma.  I have yet to test it at 30 kv.  I had to leave it behind and go to college. :(  Soon though I will be back home.  Before I left I mounted it in a wooden box.  I coated the inside of the box with epoxy and filled it with mineral oil.  I does have feed through insulators.

Note:

Text in red is a example, of the one I built ¦¬)

Text in blue is a constant I made ¦¬)

Design:     First you must decide the following

Primary voltage PV : 240 volts

Secondary voltage SV : 30,000 volts

Secondary current SC : 0.3 amps

Working frequency f : 60 hertz

Money you want to spend on the project M : < 50 dollars

Calculations:

VA = SC * SV    9,000 va

Reg = 1 + 0.6 / (VA ^ 0.5)    1.00632 Regulation coefficient

TVA = VA * Reg    9,056 watts Total power

TPV = 1646 / (f * (TVA ^ 0.4654))    0.3950 Turns per volt

PT = PV * TPV    94.8 Primary turns

ST = SV * Reg * TPV    11,927 Secondary turns

PC = TVA / PV    37.73 amps  Primary current

PWS = log ((4467 / ((TVA ^ 0.202) * PC)) ^ 10)      12 awg Primary wire size

SWS = log ((684 / ((TVA ^ 0.202) * SC)) ^ 10)        26 awg Secondary wire size

A = 74 * PV / (f * PT)    Cross sectional area of the core in inches ^ 2 3.125 Note: the number 74 varies with what type of metal you use

Now figure out the cost of all the wire + iron core + insulation and make sure its less than M.

Read me:

    These equation are only for a iron core transformer. With a primary voltage < 1000 volts and a secondary voltage > 10000 volts.  If you are building this for tesla coil use make sure that the secondary insulation is at least 3 times the secondary voltage.  Don't ever short one of the secondary leads from a transformer built from the above information without some sort of current limiting device.  It would draw anywhere between 5 and 10 times its rated power.  If you did a pretty cloud of smoke would rise and tears would form in your eyes. ¦¬)