Top IPC subclasses
1
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H01F
|
7
|
magnetsinductancestransformersselection of materials for their magnetic properties
|
2
|
H02M
|
4
|
apparatus for conversion between ac and ac, between ac and dc, or between dc and dc, and for use wit
|
3
|
F01N
|
3
|
gas-flow silencers or exhaust apparatus for machines or engines in generalgas-flow silencers or exha
|
4
|
B23K
|
3
|
soldering or unsolderingweldingcladding or plating by soldering or weldingcutting by applying heat l
|
5
|
F04B
|
2
|
positive-displacement machines for liquidspumps
|