Inside

The workshop, up close.

Copper, steel and patience — how a transformer is built, and how a burnt one is brought back.

Builds: Dry, oil, toroidal
Rewinds: Transformers
Repairs: Motors, any make
Where: Srinagar

01The craft

Copper, steel and patience.

A transformer is a simple idea — two windings on one core — made well only by care. The copper has to be the right gauge, the layers insulated, the core tight, the whole thing dry.

A rewind is the same work done backwards first: take the old winding out, learn from it exactly what went in, and put it back better.

A tightly wound spool of bright copper wire — Winding wire

A gloved hand holding the stripped copper ends of a cable in front of a work jacket

Joining the leads

A machinist in blue overalls and a cap working at an old lathe in a workshop — Machining at the bench

02At the bench

How a winding is brought back.

Record
Before anything is cut, the old winding is measured: turns, wire gauge and connection, written down.
Strip
The burnt winding comes out and the core or stator slots are cleaned back to bare steel.
Insulate
Fresh slot and layer insulation goes in, so the new copper has a clean, dry bed.
Wind
New copper, wound to the recorded data — not guessed from a similar unit.
Dry and varnish
The winding is dried and varnished so it holds together under heat and vibration.
Test
Insulation, ratio and current are checked on the bench before the unit goes home.