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  • CONSTRUCTION A TRANSFORMER

  • The transformer is an electrical component

  • designed to change the level of voltage and current,

  • according to need.

  • Operation

  • Electronic devices

  • used to operate at different voltage levels

  • delivered by the public.

  • To operate these devices require a transformer.

  • A transformer consists of a core

  • of laminated silicon iron,

  • on which is wrapped

  • a coil of insulated copper wire,

  • called magnet wire.

  • The first coil receives power from the grid.

  • This coil generates a magnetic field

  • which induces a motion

  • of the electrons in the second coil,

  • producing a different voltage

  • and current at the output.

  • The difference of turns

  • of wire between the primary and secondary coil,

  • creates a proportional difference between

  • the input voltage

  • and output voltage of the transformer.

  • The processor that we will build in this case

  • is 18 to 18 Volts AC,

  • ideal for the amplifier of 300 watts,

  • we teach to build on our Web site,

  • construyasuvideorockola.com.

  • Materials

  • Double layer magnet wire

  • Copper wire is coated with dielectric varnish

  • used in the manufacture of generators,

  • alternators, coils, electric motors,

  • power transformers, etc..

  • Silicon iron sheets

  • These silicon iron sheets

  • come in the shape of the letter (I)

  • and letter (E) interspersed,

  • forming the core of the transformer.

  • Waxed paper or pressboard

  • This role is used to isolate the windings or coils

  • of wire together.

  • It has a paraffin bath,

  • which makes it flexible and ductile,

  • it also seals out moisture

  • and gives heat resistance,

  • preventing it from crystallizing.

  • Masking tape

  • It is used to hold paper and wire,

  • between the windings.

  • Foot screws and squares

  • The screws used to tighten the plates of iron

  • and squares or brackets

  • are used to adjust the transformer

  • to the chassis or cabinet.

  • Formwork

  • Square one reel is used as support for winding the wire

  • and prevent spreading,

  • helping the smooth narrowing of the wire.

  • The formwork are available in various materials such

  • as plastic, cardboard and fiberglass.

  • The geometer Jaime Rios,

  • 7 planes designed formwork,

  • which may be downloaded from our Web site

  • and then build them in straw or cardboard.

  • It must make the pieces of cardboard,

  • gluing with glue for wood,

  • reinforced with masking tape

  • and a coat of varnish,

  • which protects the reel from moisture,

  • giving consistency and durability.

  • Calculation of transformers

  • Before the construction of a transformer,

  • you should study our article on how

  • to calculate a transformer.

  • To calculate the number of turns of wire,

  • we take the core area is the product of multiplying

  • side by side of the mold.

  • In this case we have a formwork of 5 by 3.8 inches,

  • which gives us a core with an area of 19 square centimeters.

  • We take the constant 42

  • and divide by 19 for 2.21 turns per volt.

  • As on the public of our country

  • we have a voltage of 115 volts,

  • multiply by the number of turns per volt.

  • Now we know how many laps given

  • in the primary winding.

  • For the secondary winding,

  • in this case 18 volts,

  • multiply by the number of turns per volt

  • and 40 turns of wire get doubles.

  • Construction

  • We drilled the mold, where you will enter

  • one end of the primary winding wire.

  • Preparing the magnet wire

  • We removed about 5 mm rubber coating.

  • It pre tinning the tip of the cable,

  • joining welding, soldering iron

  • and workpiece at the same time.

  • It is necessary to sand a few millimeters

  • from the tip of the wire,

  • to remove the varnish layer dielectric isolation

  • from the electricity and moisture.

  • pre tinning wire tip copper

  • We connect the wire and cable,

  • melting the solder with the soldering iron.

  • Use thermal shrinking isolator 3 mm to isolate the joint.

  • This heat-thermal shrinking isolator,

  • isolating and taking the form of what it covers.

  • Insert the wire through the hole.

  • The wire is secured considering leaving

  • the union within the mold.

  • Secure wire with masking tape.

  • Winding the wire

  • Wrap the wire of the primary winding from bottom to top,

  • from left to right,

  • pressing well and taking care not to ride around

  • on another and no spaces between the turns of wire.

  • This is done in an orderly and neat,

  • to fit all necessary turns.

  • We recommend that every 100 turns of wire,

  • stick a piece of tape with the number

  • of revolutions and so,

  • where should you lose track of laps,

  • only to be returned to the last tape recorded

  • the number of turns.

  • When you finish all the laps

  • winding the primary winding,

  • cut the wire

  • We removed the dielectric varnish,

  • using a piece of sandpaper

  • We took a piece of wire

  • and 5 mm retired rubber coating.

  • Tin the tip of the cable

  • Tin the tip of the wire

  • And join the cable and wire with the soldering iron.

  • We cover the union with thermal shrinking isolator

  • Spaghetti 3 mm and apply heat.

  • Insert the cord into an outlet slot.

  • Isolating the primary winding

  • The primary and secondary windings

  • are isolated from each other,

  • masking tape and wax paper or pressboard.

  • The wax paper should cover the entire wire

  • and secured with masking tape.

  • Then the paper is covered with more tape.

  • Make sure there are no spaces through which they can play

  • the primary with the secondary winding.

  • Ensuring the secondary winding

  • To wind the secondary winding,

  • as in this case is a central TAP transformer,

  • wire is wound twice.

  • Secured with tape masking and rolled from left to right,

  • pressing well and taking care not to ride around

  • on another

  • and no spaces between the turns of wire.

  • At the end of winding, cut the wire

  • and insert the tips of the tail end of the wire

  • in the output slots.

  • We sand the ends of the wire,

  • to remove the dielectric insulating layer of varnish.

  • Detecting the central TAP or the transformer’s center point

  • We must identify the ends of the windings,

  • measured continuity with a multimeter.

  • It is necessary to join the leading edge of a winding,

  • with the tail end of another winding.

  • The starting point of a secondary winding

  • must together with the tip end

  • of the other secondary winding,

  • thus forming the central TAP.

  • In order to weld the central TAP point or center,

  • remember to sand the pieces of wire,

  • so that there is adhesion of the solder and good driving.

  • Recheck in continuity with the multimeter,

  • which has conduction between the three tips

  • of the secondary winding.