I'm an electrical engineering student, and I am working currently on a project using a microwave transformer, and creating something like Jacob's ladders.

If I take two microwave transformers and connect them in cascade, would I then get 22kV at the 2.2kV output of the latter?

I'm guessing I would have to limit the current so that it won't melt, or would it melt either way?

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    \$\begingroup\$ maybe you mean cascade not series \$\endgroup\$ Dec 14, 2022 at 11:32
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    \$\begingroup\$ Perhaps rewind the secondary for 22 kV and job done? 22 kV is seriously high so isolation and wire termination won’t be easy. \$\endgroup\$
    – winny
    Dec 14, 2022 at 11:37
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    \$\begingroup\$ I would imagine it likely that if you cascaded 2 MOV transformers the insulation would break down. I don't know that for sure, but MOV manufacturers aim to minimize costs, so I would expect that the absolute max voltage tolerated is not much higher than needed. \$\endgroup\$ Dec 14, 2022 at 11:38
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    \$\begingroup\$ Conceptually it works but in reality you’d hit a number of problems. The insulation is not designed for 22kV so no go. As well, feeding 2.2kV into a 220V primary would cause the transformer to saturate due to excessive magnetic field. Limiting the current might stop the smoke, but not resolve this fundamental problem. So, no go on both counts. Also note the inherent dangers dealing with high voltages. This stuff will kill you if you’re not careful. \$\endgroup\$
    – Kartman
    Dec 14, 2022 at 11:40
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    \$\begingroup\$ Also, transformers have a "turns per volt" requirement to avoid saturation. Again, because of the manufacturer's aim of minimizing costs, I doubt a MOV transformer could take the output of another MOV transformer as its input. \$\endgroup\$ Dec 14, 2022 at 11:43

1 Answer 1


Perfectly ideal transformers will work in cascade (secondary of the first transformer feeding the primary of the second) but, in the real world, it'll end in tears. This is due to the magnetization inductance of the primary of each transformer (nowhere near ideal, not even close).

In microwave transformers, the magnetization inductance is about 1 henry or maybe even a bit smaller so, the second transformer's primary will load the output of the first transformer so much that you'll probably not get more than a few hundred volts on the second transformer's secondary.

In short: it won't work.


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