In this case, the windings will occupy much less space than with random winding, and there will be minimal possibility of breakdown between the turns. Having finished the row from right to left, they wind the next row in the opposite direction. After each row (layer) of the wire, a paper strip or PTFE film is laid, which should fit tightly across the width between the cheeks of the frame. Do not allow wire to enter between the gasket and the cheek of the frame. The thickness of the winding is slightly larger at the place where the output conductors are located, so they must be placed on the side of the coil, which after assembly of the core will not be placed inside the core, but outside it. The findings are passed through holes in the cheeks of the frame. From the transformateur à sec you can have the best deal now.
Transformer repair for power supply of control and signaling circuits
The enameled wire used for winding should be covered with a continuous uniform layer of enamel film, the surface of which should be smooth, shiny, without bubbles, foreign bodies, without mechanical damage to the upper layers of the metal. The wire is taken of the same diameter and retains the same number of turns, otherwise it will not fit in the frame.
After winding all the windings, the transformer coil is glued on top with a new cambric tape or tape removed from the transformer before being unwound to protect it from mechanical damage and dust.
Assembly of transformers after repair
Before assembling the core, check the condition of the plates, straighten the bent. If there are traces of rust on the iron plates, they are cleaned of rust and covered with a thin layer of bakelite varnish. When assembling, the middle branch of the U-shaped plate is inserted inside the coil frame, the extreme branches are left outside the coil. The assembly is carried out so that the plates are installed alternately, either on one or the other side of the coil, which is necessary to create a closed magnetic flux in the core.
When collecting the core, pay attention not to crush the plates and at the same time not damage the coil frame. Transformer iron plates are stiffer and seldom crumple during core packing. Permalloy plates are thinner, so they often crease, bend, which makes assembly difficult. The last two or three plates are put in place by light strokes of a wooden hammer. Then the core is crimped in a vice and, additionally, with the help of a wooden hammer, two or three more plates are installed. If the plates are not full, then when you turn on the transformer is buzzing.
At the end of the core assembly, fixing bolts are inserted and the core is pulled together. To increase the moisture resistance, heat resistance, electrical and mechanical strength of the transformer windings, the windings are impregnated with insulating melamine-liftal varnish.
Transformer repair for power supply of control and signaling circuits
At the end of drying, an electric power supply is connected to the transformer and a voltage is checked on its windings, the integrity of the windings, insulation resistance, and no-load current.
They also check whether the transformer is buzzing a lot, which may be the result of not only poor core packing, but also insufficient tightening.
