A coil to which the input voltage is applied in an inductively coupled circuit, particularly a transformer.
Found on https://www.encyclo.co.uk/local/20820
primary windingnoun coil forming the part of an electrical circuit such that changing current in it induces a current in a neighboring circuit; `current through the primary coil induces current in the secondary coil` Found on https://www.encyclo.co.uk/local/20974