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The voltage coils used are switching, disconnecting, holding, time delay, braking, etc.; by the type of current - direct current and alternating current; according to the design and technological basis, voltage coils are divided into frame and frameless. Frame coils have one- and two-section versions.

Frameless coils are easier to manufacture, but they have a reduced heat transfer capacity, reduced mechanical strength of the insulation, and do not have structural elements that ensure their reliable attachment to certain parts of the apparatus. The main technological operations are as follows: procurement operations, winding, impregnation and drying of the winding or compounding, finishing operations, step-by-step control with intermediate and final tests of the winding.

The scope of procurement operations includes: winding equipment with frames (for frame execution) and winding wire; selection of insulating materials in accordance with the specifications of the assembly drawings of the coils; preparation of conclusions - hard or soft and other materials necessary for winding work, usually provided for in the technological documentation for winding work.
The paper used for interlayer insulation in order to increase the penetrating power of the impregnating varnish and compound is perforated by punching round holes in a checkerboard pattern. Cutting into narrow strips of paper, micanite, cardboard and other sheet insulating and cushioning materials is usually carried out using lever scissors.
All prepared materials before entering the winding section are accepted by the Quality Control Department.

Manufacture of coil frames.

On fig. 3-35 shows one of the versions of the coil frame of the prefabricated structure.
The sleeve 1 is made bent from galvanized steel sheet with a fixed end clearance of 2-3 mm; insulation 5 is made by crimping and baking from flexible micanite or fiberglass based on thermosetting resin. Washers 2, 3 and 6 are made by stamping. When assembling the frame with the nozzle of the washers on the sleeve 1, the washers 3 are glued to the washers 2 and 6 with an insulating varnish. The end washers 2 are fastened by bending in the adaptation of the antennae 7 of the sleeve 1. The corner insulation 4 is a varnished fabric tape wound in several layers with gluing with an insulating varnish, pre-cut on one side to half its width in increments of 5-8 mm.
Prefabricated frames are made from isolite sleeves and getinax end washers by gluing.
Coil frames made of plastics have a number of advantages over prefabricated frames; their manufacture is less laborious; they are more monolithic; have stable dimensions and high insulating properties; when using press material brand AG-4, the frames have high mechanical strength.
On the frames of the coils, special processes are provided, with the help of which the coils are attached to the magnetic circuit.

Manufacture of frameless coils.

The specified drawing dimensions of the internal holes of frameless coils and their ends are entirely determined by the shape and dimensions of the mandrels. They are made collapsible with an allowance of dimensions that take into account the subsequent imposition of the main insulation of the internal holes and ends of the coils.
The main insulation of frameless coils consists of cutting sheet insulating material (flexible micanite, film cardboard, glass mica, etc.), which provides a given level of insulation of the coil winding from grounded or bipolar metal parts of the apparatus.
Solidity of frameless coils is ensured by inter-row spacers of capacitor or other paper with folded edges for the first turns of subsequent rows, several ties of winding turns with cotton tape, external bundling of coils and, finally, impregnation or compounding of their windings.

Coil winding.

Semi-automatic machines for open winding of multi-row windings are most widely used. The design feature of these machines is to ensure strict coordination between the rotation of the spindle with the frame or the mandrel of the coil and the movement of the unfolding device with the conductor equipped with a reversing device.
The values ​​​​of winding machines with an electric drive are distinguished by the maximum diameters of the windings of the coils processed by them, the lengths of the latter and the diameters of the winding wires.
When winding on semi-automatic machines, the share of manual operations is: installation of a frame or mandrel on the machine; work related to the manufacture of the initial and final conclusions of the coil windings; adjusting the tension of the winding wire with the setting of the conductor; soldering wires; isolation of bare places of winding; fixing the winding leads.
Automatic operations include: layout of the winding wire; row stacker reverse; supply of inter-row paper pads; stop the machine when the wire breaks and when the specified number of turns of the winding is reached.
In mass production, high-performance multi-spindle single-spindle (Fig. 3-36, a), multi-spindle (Fig. 3-36, b) and multi-position winding machines are beginning to be introduced.


On fig. 3-37 shows a schematic diagram of a six-position carousel-type winder for winding bobbin coils. The machine has six spindles 3 evenly spaced on the turntable 1.


At the first position from the carcass magazine, the feeder 4 places the coil carcass onto the spindle 3. The spindles are mounted on faceplates 2. After turning the table in position II, the coil is wound with spools 5 with a wire and a tension control mechanism; in position III, the coil leads are fixed using a gluing device 6; at position IV - control of the winding for the presence of short-circuited turns with prefix 7; in position V - removal of defective coils; in position VI - removal of suitable coils from the spindle.
In large-scale and mass production, a promising direction is the use of high-performance specialized winding machines and winding machines with program control instead of universal ones.
Winding work ends with the acceptance of the QCD with the measurement of the winding resistance, the quality of the leads, banding, checking the preliminary geometric dimensions. The winding of the AC coils must be checked for the absence of short-circuited turns.

Winding technology

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Production of radio equipment

Winding technology

Winding works occupy a significant place in the production of radio equipment. Winding is understood as the technological process of laying wires to obtain coils of circuits, windings of transformers, chokes, relays, resistors and other elements of radio equipment.

Below, mainly, the issues of manufacturing inductors - the main elements of oscillatory circuits, filters, chokes, transformers - are covered.

Types of windings. Depending on the functional purpose, different requirements are imposed on inductors in terms of inductance, quality factor, stability, self-capacitance, dielectric strength, etc.

The functional purpose also determines the values ​​​​of permissible deviations of the inductances of the coils during their production.

Coils for high and intermediate frequency circuits are manufactured with an inductance tolerance of ± (0.5-1.5)%, feedback coils with a tolerance of ± 10%.

Tolerances for the inductance of high-frequency chokes are set in such a way that the smallest value that can be obtained during production does not go beyond certain limits.

Inductors of elements of low-frequency circuits (chokes and transformers) are manufactured with a tolerance of ± 10%,

The current-carrying part of the coil - the winding - is characterized by the following parameters: winding pitch p, wire diameters d and du3, frame diameter dK, distance between turns A and wire laying angle cp.

The winding pitch p is the displacement of the end of the coil relative to its beginning, measured by linear measures. The winding pitch with a dense stacking of turns will be equal to da3, and with

Rice. 1. Schematic representation of the winding pitch and the laying angle of the wire: a - continuous winding, b - step winding

laying wire with gaps between turns is determined by the sum d + A or dm + A. The ratio of the winding pitch p to the length of the projection of the perimeter of the turn F on a plane perpendicular to the axis of the winding determines the tangent of the laying angle of the wire<р:

All windings wound on frames can be divided into two main groups - single-layer and multi-layer.

A single-layer winding is characterized by a low self-capacitance, ease of manufacture, and is wound with a pitch equal to daa \ dm + A or d + A. In mass production, coils with such windings have a small spread of parameters, but at high inductances, the dimensions of such windings become significant, which limits their area of ​​application.

Single-layer windings can be divided into ordinary, bifilar and toroidal. Ordinary windings are used for the manufacture of inductors; bifilar - for the manufacture of non-inductive resistances, and toroidal - for the manufacture of rheostats, transformers, etc. A feature of the toroidal winding is the absence of an external magnetic field in it. This winding is placed on toroidal frames, its coils are arranged radially. The winding pitch is determined by the inner circumference of the toroid and is usually equal to da3 or daa + A.

Multilayer windings are used to obtain a sufficiently large inductance with relatively small coil sizes. According to the principle of winding, multilayer windings can be: ordinary, multilayer bifilar, sectioned induction, sectioned non-inductive, biscuit, spiral, pyramidal, universal, cross and toroidal.

To isolate the layers of the winding, gaskets made of capacitor, telephone or cable paper are used. The winding is carried out in rows: one row is wound from right to left, the next is vice versa, etc. The wire for these windings is used only insulated, and the winding pitch p is equal to yal.

A multilayer winding is characterized by an increased potential difference between the turns located in adjacent rows along the edges of the winding, so it must meet stringent electrical strength requirements. A feature of all multilayer windings is the presence of a large self-capacitance. To reduce the value of its own capacitance, the winding is made sectioned or special types of windings are used: universal and cross.

The universal winding is characterized by the fact that the coil of wire has two or more kinks in one revolution around the frame. With this winding, the turns intersect each other at a certain angle. The larger this angle, the smaller the self-capacitance of the coil. However, for design reasons, this angle cannot be made arbitrarily large, it cannot exceed the limit value for a given type of insulation and wire diameter. The advantages of a universal winding include high inductance, compactness and high mechanical strength. The latter circumstance allows it to be used in frameless coils (the frame is required only during the winding process).

If, during winding, a coil of wire through a turn has not reached the starting point, such winding is called universal with a lead (Fig. 2, a). If, during winding, the turn through the turn came up to

Rice. 2. Universal winding: a - advance laying, 0 - delay laying

the previous turn, but on the other hand, such winding is called universal with delay (Fig. 2, b). Usually, a universal winding is made with a diameter D not exceeding 25-30 mm and a width b not exceeding 8-10 mm.

To obtain large inductances, a cross winding is used (Fig. 3). By the nature of the wire laying, it resembles a universal one, but differs in that it has only two kinks. Before winding, the wire is fixed on the frame, then several turns are made with a certain step (the turns go from left to right). Having reached the right end, they make an inflection, and the winding is carried out in the opposite direction. Having reached the left end, they again make an inflection, etc. This method of winding provides a sufficiently small intrinsic winding capacitance.

The type of winding is selected depending on the functional purpose of the developed node.

Winding machines. For the manufacture of windings, special winding machines are used. They are divided into three main groups: for ordinary, universal and toroidal windings.

For ordinary winding, machines of different designs are used. A typical diagram of such machines is shown in fig. 4. The machine is driven by a special electric motor /, which transmits rotation through a belt drive with a pair of three-stage pulleys to an intermediate shaft.

Rice. 3. Cross winding

With the help of a friction clutch located on the shaft, a smooth start and stop of the machine is provided, which is necessary to prevent wire breaks. The device is turned on by a lever through the plug.

By means of a gear transmission, rotation is transmitted to the spindle and the mandrel fixed on it, on which the coil frame is put on.

Rice. Fig. 4. A typical kinematic diagram of a winding machine for row windings: 1 - electric motor, 2 - intermediate shaft, 3 - lever, 4 - friction clutch, 5 - fork, 6 - gear pair, 7 - stacked turns counter, 8 - interchangeable gears, B - worm pair, 10 - thrust, 11 - cam, 12 - adjusting screw, 13 - wings, 14 - backstage stone, 15 - leash, 16 - wire, 17 - wire driver, 18 - winding frame, 19 - spindle, 20 - mandrel

The coil counter and the wire laying mechanism are also driven from the machine spindle.

The movement from the spindle through interchangeable gears is transmitted to the worm pair and the cam, and then through the rod and the link to the leash.

Setting the machine to the required winding width is done with a screw by changing the position of the backstage stone.

Known values ​​of the length of the winding and the diameter of the wire with insulation determine the point of intersection of the lines indicating

Rice. 5. Nomogram for the selection of replacement gears for the winding machine SRN -0.1

these quantities. Then, along the nearest (from this point) inclined line, they follow down and find in the column on the right or below the values ​​​​of the number of teeth of the machine's replaceable gears - Zb Z2, Zs, Z4.

However, it is not always possible to obtain exactly the required pitch by selecting interchangeable gears, especially for winding thin wires with a diameter of less than 0.1 mm.

Setting up a machine with interchangeable gears is a laborious process that requires a qualified adjuster.

Winding machines with stepless, or frictional, step adjustment are free from these shortcomings, which makes it easy to quickly adjust various winding steps.

Rice. 6. Wire tension mechanism: 1 - ratchet wheel, 2 - lever axis, 3 - spiral spring, 4 - handle for tightening the spring, 5 - lever, 6 - overturning roller, 7 - roller axis, wire, 9 - mandrel for attaching the spool , 10 - spool with wire, 11 - brake band, 12 - brake disc

An important unit of the machine is a device for attaching a spool with wire and. wire tensioner. The mechanism (Fig. 89) serves to create a certain tension of the wire and maintain it constant during the winding process.

Laying the wire directly on the frame is carried out by the driver. On fig. 7 shows typical designs of drivers, the choice of which depends primarily on the type of winding, as well as the diameter and brand of wire. Rod drivers with minimal axial play are used for ordinary windings with thin wires; roller drivers, providing minimal friction and kinks, are used for ordinary windings with wires of medium and large diameter. The fork driver is characterized by transverse (axial) rigidity; it is used for cross windings. Drivers with a hole are used in toroidal winding machines. The working surfaces of the drivers must be polished and must not have sharp edges and corners so as not to damage the wire.

Rice. 90. Wire drivers. a - with two rollers, b - in the form of two rods, c - with a hole for the wire, d - in the form of a fork (with a pressure spring); 1 - leash, 2 - wire, 3 - rollers, 4 - fixed part of the driver, b - rotary part of the driver, 6 - rods, 7 - pressure spring, 8 - wire guide

carcass on the machine spindle, its removal and minimal runout during winding. On fig. 10 shows various designs of winding mandrels.

The simplest mandrel is a rod mandrel, consisting of a rod with a threaded end and a tail. The coil frame is fixed with a nut (wing or round) on a blank, previously put on the mandrel rod.

For mass radio production, a quick-release mandrel is most acceptable.

For multi-coil winding, use the mandrel shown in Fig. 10, e. It has a swivel joint to facilitate the installation and removal of frames, as well as spring pads that fix the position of the spool frames.

The universal mandrel is a clamping chuck with two sliding jaws 18, through which the frame is fixed.

Rice. 10. Winding mandrels: a - simple rod, b - quick-detachable with a spring clamp, c - for a multi-reel machine, d - universal sliding mandrel-chuck; 1 - stop screw. 2-shank, 3-rod, 4-round knurled nut, 5-sleeve, 6-spring 7-fork, 8-latch, 9-frame, 10-swivel joint, 11-spring gasket between frames, 12-fixing holes , 13 - center of the tailstock of the machine, 14 - base, 15 - body, 16 - screw with squares at the ends, 17 - split lock washer, 18 - sliding clamping jaws

The industry produces many types of winding machines for ordinary windings, two of which are shown in fig. 11 and 12. The machine shown in fig. 11, designed for the manufacture of windings with wire from 0.05 to 0.5 mm.

The semi-automatic winding machine PR-159 has a friction transmission mechanism for stepless adjustment of the wire layout step and automatic stop after winding a specified number of turns or when the wire breaks. The machine is designed for ordinary multilayer winding on coil frames; its main data: the diameter of the wound wire is from 0.08 to 0.6 mm, the largest diameter of the coil frame is 90 mm, the winding length is 180 mm, the number of spindle speeds is 6, the number of spindle revolutions is 78, 137, 240, 1600, 2800, 4900 rpm min; electric motor power 0.4 kW, dimensions 1110 X 585 X 1800 mm, weight 250 kg.

Rice. 11. Machine for ordinary windings: 1-frame, 2 - a casing that closes the transmission mechanism of four interchangeable gears, 3 - revolution counter, 4 - spindle, 5 - leash, 6 - rack, 7 - spool, 5 - mandrel

The semi-automatic machine PR-160 is similar in design to the machine G1R-159; the diameter of the wound wire is from 0.2 to 3 mm.

Increasing the productivity of winding work, their mechanization and automation is an important issue that represents a large field of activity for innovators and designers. Winding machines of the latest brands have special devices designed for automatic laying of interlayer insulation.

In large-scale and mass production, semi-automatic multi-coil machines are used that simultaneously stack up to twenty or more windings on long frames of round, square or rectangular sections.

Devices have been developed that allow detecting short-circuited turns in the process of winding inductors using a special electronic circuit.

Great opportunities for mechanization and automation are provided by the use of winding machines with program control.

Machines for universal windings, unlike machines for ordinary windings, do not have a permanent worm pair; here, interchangeable cams are used, made for a certain winding width, or an additional rocker device that allows you to adjust the winding width to some extent (Fig. 13).

Gears serve to provide the desired gear ratio from the spindle to the cam. For the selection of gears, special nomograms are used for universal windings.

For toroidal winding on closed-type frames, a special winding machine is used, the principle of operation of which is shown in fig. 14. The wire is pre-wound on a spool inserted into the coil frame. The coil frame is mounted on the machine table and driven into rotation by means of two leading and one pressure rollers. With a slow turn of the frame, the spool rotates, from which the wire is wound onto the frame. The machine must be set up so that after laying one turn, the frame rotates by the amount of the winding step.

The kinematic diagram of the machine for toroidal windings is shown in fig. 15. The spool of the machine is a system of two rings inserted one into the other. The rings have a removable sector, through which a toroidal frame is inserted into the spool.

Rice. 12. Semiautomatic device PR-159 for ordinary winding

The spool rings are rotated by an electric motor through a belt drive, gears and a gear fixed around the circumference of the spool rings. The frame is fixed in the clamping device by means of three spring-loaded self-centering rollers.

Rice. 13. Machine with a cam for universal winding: a - machine kinematic diagram, b - cam design; 1 - electric motor, 2 - friction mechanism, 3 - transmission mechanism, 4 - drive shaft, 5 - cam, b - spring pressing the drive rod to the working surface of the cam, 7 - drive rod, 8 - drive, 9 - laid wire, 10-roller, 11-wire driver! 12-frame, 13-arbor, 14 - spindle, /5-revolution counter, 16 - inner corner of the cam, 17 - outer corner of the cam, 18 - locking screw for fastening the cam, 19 - working end surface of the cam, 6 - height difference between outer and inner corners of the working surface of the cam, equal to the width of the winding

The roller has a kinematic connection with the spool by means of a transmission mechanism, due to which, in one revolution of the spool, the frame rotates through an angle equal to the winding pitch. Kinematic connection is carried out from the gear through the gears, eccentric, rocker mechanism, gears, worm gear and gears.

Before starting work, the determination of the amount of wire necessary for the manufacture of the winding is wound on the spool of the machine (the wire is supplied from the supply coil). After that, the end of the wire is fixed on the frame, and the machine is turned on for a working stroke, during which the wire is unwound from the spool and placed on the frame. Wire tension is adjusted by braking the spool. The winding speed on the machines of this group is much lower compared to other machines (up to 300 turns per minute).

On fig. 16 shows a general view of the desktop machine model SNT-5 for toroidal windings. The machine is designed for circular and sectional winding of wire on toroidal cores with the smallest hole diameter after winding 5 mm.

On fig. 17 shows a general view of a similar machine tool model SNT-12M. The machine is also designed for circular and sectional winding of wire on toroidal cores with the smallest hole diameter after winding 12 mm.

Both machines consist of standard units: a drive, a wire feeder, a shuttle head, two tables (for circular and sectional winding) and a control panel.

During the winding process on the machines, you can manually adjust the amount of feed, as well as control the integrity of the wire.

The tension of the wire laid on the toroid is carried out by a brake, which periodically slows down the spool in accordance with the cyclogram.

The process of winding wire on toroidal cores involves installing the toroid on the working table, filling the spool with wire and rewinding it from the spool onto the toroid.

Technical characteristics of the SNT-5 machine: the diameter of the wound wire is 0.05-0.15 mm, the smallest diameter of the coil hole after winding is 5 mm, the largest coil height after winding with the smallest inner diameter is 6 mm, the largest coil height is 12 mm, the largest outer diameter of the coil 20 mm, the smallest inner diameter of the coil with sectional winding 7 mm, the smallest outer diameter of the core 11 mm, the limits of smooth pitch control along the outer diameter 0.056 - 1.68 mm, the spindle speed (stepless control) 50-300 rpm, inner diameter shuttle and spool 45.5 mm, spool capacity 400 mm3 or 14 m of wire with a diameter of 0.05 mm, electric motor power EOR - 80 W, overall dimensions 580 x 680 X 515 mm, weight 42.6 kg.

Rice. 14. The principle of operation of the machine for toroidal winding: 1 - pinch roller, 2 - driving rollers, 3 - spool, 4 - wire, 5 - coil frame

Rice. 15. Kinematic diagram of the machine for toroidal windings: a - diagram, b - view of the store, frame and drive roller from the side, c - view of the store, frame and rollers from above; 1 - electric motor, 2 - belt drive, 3-7, Ills, 15, 17, 26, 28 - gears of transmission mechanisms, 8 - magazine rings, 9 - toroidal frame, 10 - drive roller for turning the frame, 14 - worm gear, 16 - handle for turning on the mechanical feed of the winding step, 18 - handle for manually turning the frame, 19 - handle for manually turning the magazine, 20 - rocker mechanism, 21 - eccentric. 22 - cam, 23 - stacked turns counter, 24 and 25 - support rollers. 27 - pitch setting handle, 29 - pitch setting scale, 30 - wire wound from the magazine onto the frame

Rice. 16. SNT-5 machine for winding on toroidal cores

Rice. 17. Machine SNT-12M for winding on toroidal cores

Technical characteristics of the SNT-12M machine: the diameter of the wound wire is 0.15-0.4 mm, the smallest diameter of the coil hole after winding is 12 mm, the largest coil height after winding with the smallest inner diameter is 15 mm, the largest coil height is 80 mm, the largest outer diameter of the coil 120 mm, the smallest inner diameter of the coil with sectional winding is 16 mm, the smallest outer diameter of the core is 30 mm, the limits of smooth pitch control along the outer diameter are 0.12-3.6 mm, the spindle speed (stepless control) is 50-300 rpm, the inner diameter of the shuttle and the spool is 161 mm, the capacity of the spool is 13,000 mm3 or 420 m of wire with a diameter of 0.05 mm, the power of the EOR electric motor is 80 W, overall dimensions are 580 X 680 X 515 mm, weight is 47.2 kg.

Typical operations for the manufacture of windings. The technological process of manufacturing windings consists of a number of typical operations; blanks of gaskets and output ends; tinning of conclusions; winding and fixing the ends of the winding.

The preparation of gaskets consists in cutting the gasket material into tapes of the required width, as well as cutting the tapes along the edges, if this is provided for by the drawing. The cushioning insulating material (paper, varnished cloth, etc.) is cut on lever or roller scissors.

When preparing the leads, the wire is cut into pieces of the same length (from 25 to 120 mm), the insulation is removed from them by 7-10 mm and the ends are tinned. The main brands of output wires: MGBD, MGBDO, MGSHD, MGSHDO, PMVG and MGSHV.

High-performance preparation of output wires is carried out on special equipment - automatic machines that combine cutting wires with stripping.

The tinning of the ends of wires that do not have galvanic tinning on a conductive core is usually carried out in table-type electric crucibles.

Winding the wire on the frame largely determines the quality of the winding and is the main operation of the technological process.

The winding machine is selected based on the size of the coil, the diameter of the wire and the production program. The winding process is preceded by preparatory work: installation of coils (bobbins) with wire, selection and installation of a winding mandrel; winding pitch and width setting; winding speed setting; wire tension adjustment; preparation of materials and tools for soldering. The setting of the machine is performed by the adjuster, who also makes a trial coil, and only after its verification, they begin to manufacture a batch of coils.

If the batch is small, it is more convenient to first wind the first winding on all frames, and after rebuilding the machine, wind the second winding, etc. With a large batch, it is more rational to use a separate machine for each wire (winding) diameter.

The winding speed or the number of revolutions of the machine spindle is set depending on the permissible circumferential speed of the wire, “which is determined by its diameter, as well as the size and shape of the frame.

The winding speed can be increased for round frames compared to rectangular or flat frames by 15-20%. The recommended winding speeds for the PR-159 and PR-160 machines are given in Table 1, respectively. 9 and 10.

Particular attention should be paid to the tension of the wire during winding, as it determines the quality of the winding. Insufficient tension leads to coil slippage and a change in the geometric dimensions of the winding, and excessive tension leads to mechanical

Rice. 18. Methods for terminating winding leads and intermediate point leads: a - lead wire, b - winding wire, c - the beginning and end of the winding are brought to one cheek of the coil, d - lead wire (round cross section) from the intermediate point, e - lead wire ( rectangular section with a bus) from an intermediate point, e - with a winding wire from an intermediate point, w-output wire and winding wire when connecting two windings of different diameters, z - rear screen leads, 1 - cambric tape or cotton threads, 2 - electrical insulating tube , 3 - varnished cloth LSH 1, 4 - electrical insulating cardboard EV, 5 - flexible mounting wire, 6 - copper bus, 7 - cotton threads L "0, 8 - copper screen, 9 - insulating gasket

insulation, an increase in the resistance of the wire, as well as the insertion of the wire between the laid turns.

It is necessary to fix the ends of the winding for all coils. The fastening must be strong and reliable so that the winding is not damaged during installation and operation.

On fig. 99 shows the most common ways to terminate winding leads and intermediate point leads. As a material for fixing the ends and bends, calico tape, strips of varnished cloth, nylon threads, etc. are used.

Particular attention should be paid to the quality of the electrical connection of the output end with the winding wire. The junction of the output end and the winding is laid with varnished cloth.

OJSC "ELTEZA" offers professional winding of transformer coils in Moscow, with a full quality guarantee. Our production facilities consist of a fleet of specialized machines, numbering 20 units, which allows us to quickly cope with the largest orders and always guarantee quality and meet deadlines. Experienced, highly qualified staff is the basis for the success of our activities and is able to quickly solve any problems that may arise in the course of work.

Professional winding of transformer coils

Winding transformer coils is a job that requires high precision and accuracy when performed. The slightest inaccuracy here can lead to a violation of the functionality, performance and performance of the equipment. Our company will wind transformer and choke coils and other winding products on SRN-0.5 equipment using a special wire with a diameter of 0.1 to 1.4 mm. The high productivity of our company is supported by excellent production facilities and experienced staff who can quickly complete any amount of anticipated work. When ordering the winding of transformer coils from us, you can be absolutely sure of the quality of the work performed and count on a 100% result when completing any orders.

Professional services JSC "ELTEZA"

The winding of transformer coils performed by us fully complies with current quality standards and is the basis for the popularity of this service. Our employees will always be happy to offer the most favorable prices and other conditions for the performance of work, which will become the basis for a long-term mutually beneficial cooperation. Please contact our managers or call the phones on the site. With us you can always agree on the performance of work on the most favorable financial terms.

30.03.2015

Pole coils that act as excitation windings in an electric machine are divided into two main types:

• pole coils of synchronous machines;
• coils of the main and additional poles of DC machines.

Based on the specifics of the switching circuit, the following types of pole coils with winding are distinguished:

• shunt (with parallel winding);
• serial (with serial winding);
• compound (with mixed winding).

Coils with parallel winding are produced from rectangular or round insulated wire; production of coils with serial winding - from uninsulated rectangular. Compound coils are a combination of two separately wound coils (serial and parallel wound) that are assembled together, insulated and impregnated. Depending on the manufacturer's plant and its technical regulations, the conditions for rewinding the electric motor must be met on time.

Framed and frameless reels

Coils of the main poles - both with serial and parallel winding - are frame. They are wound on a steel frame and mounted on the pole core. Before winding, the frame is manually insulated with several layers of micafolium, after which a lead plate is fixed on it, which is soldered to the beginning of the winding wire.

Upon completion of the winding, the coils are dried and impregnated, then varnished and dried again (in the open air).

Frameless coils are coils of additional poles. The winding of products is carried out on special wooden or steel templates that serve exclusively for this operation. When repairing electrical machines, wooden ones are used for winding coils of small machines, steel - for medium and large ones. To prevent abrasion of the body insulation of the coil on the surface of the pole core, a special flange made of metal or cardboard is inserted between the coil and the core.

After winding, frameless coils are subjected to the same set of operations (drying, impregnation, varnishing, drying). In electrical machines, frameless coils are predominantly used.

The PromElektroRemont company renders using both frame coils and frameless coils.

Sergey Komarov, UA3ALW

To perform “Universal” winding, you need an enameled winding wire in silk or lavsan insulation of the PELSHO, PESHO, LESHO, PELO, LELO types. Additional fibrous insulation performs two functions: it prevents the wire from slipping off the frame and from each other with oblique turns, and allows subsequent impregnation with polystyrene varnish, paraffin or ceresin to rigidly fix the arrangement of turns of the multilayer coil, which ensures high stability of its inductance.

With some skill, winding is easily done by hand. To do this, mark the frame itself, as shown in Figure 1, or wrap it with cable paper with markings applied to it. At the place of winding, two circular lines are drawn, the distance between which will determine the width of the winding. Next, two diametrically opposite lines AB and CD are drawn. The distance between them should be exactly equal to half the turn. If it is planned to wind several sections or inductively coupled coils on the frame, then marking is done immediately for all windings. Marking should be done with a non-conductive electrical dye (a simple pencil is not suitable, since its lead is made of graphite).

Next, with adhesive tape outside the markup, we fix the wire at the beginning of the winding so that it passes through point A, and with a slight tightness, we lay it obliquely along half the circle from point A to point D. At point D, we bend the wire at an obtuse angle and, holding corner with a thumbnail (for girls and young wives, this is especially good), already with less interference, we lay the wire obliquely in the opposite direction to point A. Arriving at point A, we cross the wire of the beginning, pressing it with a new turn, and immediately bend it under a blunt corner, but now in the opposite direction and begin to lay the second turn close to the first, to the right of it. At the same time, again, with the thumbnail, we hold the angle of the bend of the wire from its sliding to the center of the winding. With the acquisition of skill, this can be done with the wire of the next turn, first bending it slightly to the outside (to tighten the angle of the previous turn) and only then, pressing it with a fingernail, at an obtuse angle, inward, and laying it parallel to the previous turn.

In the process of winding, with each bend of the wire, it is necessary to tighten the bend angle to the annular marking line. Since the turns of the winding are oblique, and the winding tends to narrow when the wire is pulled, the winding is carried out with a slight tension. To obtain an even section of the winding, it is necessary to lay all the corners of the bends of the wire exactly on the line of ring markings, and make the bend sharp, holding the wire with the thumbnail of the left hand.

Before you start winding the Universal coils with a thin winding wire, you should practice such cross winding, for example, on the MGShV-0.2 mounting wire, winding it on any round rod or tube with a diameter of 15 ... 20 mm and marking the winding width 12…15 mm. To do this, you need to take a wire 3.5 ... 4 meters long and wind a narrow, high and even winding section exactly according to the markup - a kind of “pancake”, putting the entire length of the wire into the winding (Fig. 2).

After several attempts, the winding will begin to turn out even, and the necessary skills will appear, as they say, “at your fingertips”. Now you can try to wind 150 turns into a section 5 mm wide with PELSHO-0.25 ... 0.3 wire on a frame with a diameter of 8 ... 10 mm. For thinner wire, the winding width should be taken proportionally smaller. But you should not immediately get carried away with thin wires and narrow sections, without still having well-established skills. This winding requires patience, accuracy, attentiveness, fine coordination of finger movements, and if you rush, you can find frustration instead of skills. If the section turns out to be even, neat and exactly according to the markup, you can assume that you have learned how to wind the coils with the Universal winding.

At long wavelength frequencies, where there are hundreds of turns to achieve the desired inductance, it makes sense to wind a winding with a double pattern across the winding width (cross-over) and wind twice as wide. (Fig. 3).

The marking of the frame is almost the same as in the first case, but in the middle of the winding we draw another annular line. Winding is done like this. We fix the wire with adhesive tape at the beginning of the winding so that it passes through point A, and with an interference fit, lay the wire obliquely along half the circle from point A to the middle of the CD line. Next, we continue winding so that a full turn of wire ends at point B. Bend the wire at an obtuse angle and, holding the corner with a thumbnail, continue winding to the middle of the CD line, where we cross the wire of the previous turn and continue winding further. We finish the second turn at point A, where we cross the wire of the beginning of the winding, immediately bend it at an obtuse angle and lay the third turn close and parallel to the first, to the right of it. Then we continue winding, laying the wire of the new turn parallel and to the right of the previous one, and crossing the previous one at points A and B. In the middle of the CD line, the turns will intersect without a kink, and as the number of winding turns increases, the point of each new intersection will shift towards the winding. When the displacement reaches a full turn around the carcass, further winding will continue with the second layer on the already wound turns of the first layer. Here, as in the first case, it is necessary to constantly tighten the bending angles of the wire to the side lines of the ring marking and acquire the skill of maintaining the required wire tension force so that the coil turns out to be dense and so that it does not narrow from turn to turn and from layer to layer.

To fix the outer output of the coil, 10 ... 15 turns before the end of the winding, a double-folded cotton sewing thread, No. 20 thick, is placed across the turns, as shown in the figure, and winding is continued on top of it.

The location of the thread on the winding circumference must be guessed so that the end of the last winding turn is exactly in the place and from the edge where the thread loop is located. The end of the wire is cut off with a margin of the desired length and threaded into a thread loop. After that, pulling the output, tighten the loop on the reverse side of the winding and tie both ends of the thread together into two knots. The thickness of the double knot will prevent the thread from jumping out to the other side of the winding between the turns that pressed it. Fixing the external output is simple and durable.

After winding, it is advisable to impregnate the turns of the coil to choose from: liquid polystyrene varnish (a solution of polystyrene in acetone or dichloroethane), paraffin (melting a part of a household lighting candle in a tin larger than the coil, heating the jar on a soldering iron and dipping the wound coil into liquid paraffin) or ceresin ( same technology). The coil should not be impregnated with other compounds in order to avoid deterioration of the frequency properties.

If such coils are often used in your radio circle or by you personally, it makes sense to make a home-made manual machine for winding Universal coils, descriptions and drawings of which have been repeatedly published in Radio magazine. A detailed description of the work with the machine and the methodology for setting it up for a specific winding are also given in the articles.

It will not be possible to buy such a machine for anyone or for every radio club. Nobody produces them, and those that are produced are intended for large factories, designed for mass production of the same type of coils, take up a lot of space, are excessively functional, incredibly difficult to operate, cost astronomical sums and are absolutely inappropriate in a radio circle, and even more so, in a home radio laboratories.

Now about the inductance of coils wound with "Universal". Knowing the overall dimensions of the coil and the number of turns, it is possible to calculate its inductance with very high accuracy. Figure 4 shows the calculation formula, size ratios and a table of practical values ​​for the inductance of actually wound coils.

This table was compiled as follows: 150 turns of the "Universal" winding were wound on the frame of the specified diameter D1 with the specified wire; the outer diameter of the resulting winding was measured with a caliper and its inductance with an E12-1A device. Then, 10 turns were unwound and measurements were repeated 11 times until the remaining 50 turns. And so four times, with different wires, on different frames. Thus, four columns of the table were compiled.

Since with inductances of 20 ... 40 μH or less, it is better to use a single-layer winding, and it is hardly reasonable to wind less than 50 turns into a coil with the "Universal" winding, measurements with a smaller number of turns were not carried out. However, calculations of the inductances of coils with a smaller number of turns can be easily carried out using the above formula. With careful winding along the markup, the inductance calculation gives a good match (about 1% accuracy) with the measurement results.

When calculating a multi-section coil, it is necessary to take into account the mutual inductance between the sections. With the same winding direction, the total inductance of two sections located close to each other (one section is partially in the magnetic field of the other) is determined as follows:

L total =L1+L2 + 2M

If there are three sections under the same conditions, then: L total =L1+L2+L 3 + 2M 1-2+2M2-3+2M 1-3; where:

M 1-2- Mutual induction between the first and second sections;

M 2-3- Mutual induction between the second and third sections;

M 1-3- Mutual induction between the first and third sections.

If the sections are arranged in a row, one after the other, at the same distance, then M 1-2 =M 2-3. Mutual induction through the section, - M 1-3 will be very small due to the large distance between the sections and the quadratic nature of the decrease in the magnetic field strength depending on the distance between them. When calculating the inductance of multi-section coils with practical accuracy, the mutual inductance between sections located at a distance greater than their outer diameter can be safely neglected. The mutual inductance of coils spaced at a distance greater than their diameter should be taken into account only in those cases when communication between the circuits is carried out through it.

It follows that in order to obtain the maximum inductance of a multi-section coil, the sections must be located as close to each other as possible, then, with the same number of turns and active resistance of the wire, the total inductance will be greater due to mutual inductance. However, sections should not be placed at a distance closer than 2 mm, since when winding the next section close to the previous one, it is very difficult to lay turns and bend the wire accurately.

The optimal ratio of the coil shape to obtain the minimum active resistance at maximum inductance is when the section width is equal to the winding thickness, and the average winding diameter is 2.5 times the section width. It should be noted that at high frequency the optimum for the minimum active resistance does not coincide with the optimum for obtaining the maximum quality factor, and for coil sizes acceptable for compact design, there is a tendency to increase the quality factor with an increase in the average diameter, while maintaining the same width and thickness of the winding.

For example, let's calculate the inductance of a five-section choke with "Universal" winding with a section width of 5 mm, a distance between sections of 2.5 mm, containing 100 turns of PELSHO - 0.25 wire in each section, wound on a resistor VS-2W with R ≥ 1MΩ.

Since the surface of the resistor is slippery, we wrap it with two layers of cable paper 37 mm wide, 55 mm long and mark the winding sections on it. At the same time D 1 = 8.5 mm. For PELSHO-0.25 wire, the insulation diameter is 0.35 mm, the winding looseness coefficient k n= 1.09 (experimental value; can be calculated from the table in Fig. 5).

Winding dimensions: C =n (k nd) 2 /l = 100 x (1.09 x 0.35) 2 / 5 = 2.9 mm. D2=D1+2C= 8.5 + 2 x 2.9 = 14.3 mm. D = (D2+D1) / 2= (14.3 + 8.5) / 2 = 11.4 mm; l= 5 mm = 0.5 cm;

Inductance of one section (Fig. 4) :

L 1 \u003d 0.0025 πn 2D 2 / (3D+9l + 10 c)= 0.0025 π 100 2 11,4 2 / (3x11.4 + 9x5 + 10x2.9) = 94.3 μg.

Interestingly, measuring the inductance of a coil wound according to the indicated dimensions gives a result of 95 μH (Fig. 5). Given the inaccuracies in manual winding, this is a very good match.

To determine the mutual inductance between the sections, we calculate the ratio (Fig. 6):

r 2 / r 1 = √([(1 - a /A) 2 + B 2 /A 2 ] / [(1 + a/A) 2 + B 2 /A 2 ]) for five pairs of points.

Average section radius: a = (8.5 + 14.3) / 4 = 5.7 mm;

For points 0-1: A = a = 5.7 mm; B = 7.5 mm.

r 2 /r 1 = √{(7,5 2 / 5,7 2 ) / [(1 + 1) 2 + 7,5 2 / 5,7 2 ]} = √(1,7313/5,7313) = 0,5496;