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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.

  • It is very important to be sure to correct binding center point.

  • For this we must remove the two wires and re-measure.

  • There should be continuity between the two wires.

  • Again covered with masking tape and wax paper.

  • The secondary winding must be completely covered.

  • The additional winding is 12 volts.

  • To find the turns of wire,

  • 12 volts multiplied by the number of turns per volt.

  • The result is 27 laps for the additional winding.

  • This winding feeds a preamplifier,

  • which will complement the saving amplifier

  • put another transformer.

  • Like the previous windings

  • is necessary to solder a wire to copper wire

  • and masking tape on to roll the additional winding.

  • Wire is wound down up to adjust the point

  • of beginning with the turns of wire and finish up.

  • For this transformer only needed 27 laps,

  • which are the result of multiply 12 by 2.21 volts

  • turns per volt.

  • At the end of winding turns of wire

  • for the additional winding,

  • top weld wire to plastic coating wire.

  • Remember to sand the tip of the wire,

  • soldered to the cable

  • and insulate with thermal shrinking isolator.

  • At the time of the auction of the transformer,

  • is covered with tape again,

  • isolating the additional winding.

  • Then

  • with a piece of waxed paper or pressboard,

  • we strengthen the part where the wires join

  • the main secondary winding,

  • with the output wires.

  • We sand the ends,

  • removing the dielectric coating,

  • allowing the adhesion of the solder.

  • Tinning tips

  • And the cable braid tinned over the wire.

  • Now, apply plenty of solder,

  • until completely cover the cable.

  • The welds must be perfect,

  • since this depends on no loss of current.

  • We cover the junction

  • with thermal shrinking spaghetti,

  • so that fully cover the welds.

  • Imprisoned cable joints

  • with wire on the front of the transformer.

  • We put a piece of wax paper,

  • covering the joints and secured with masking tape.

  • To give a good finish to our transformer winding

  • is covered with a strip of cardboard

  • coated with adhesive paper.

  • Placing the iron-silicon sheets

  • Now comes the process of placing the sheet

  • or sheets of iron-silicon.

  • We shaped plates (E)

  • and we introduced into the mold,

  • sandwiching a one hand and the other on the other side.

  • Be careful not to lock them

  • or fit of two or more sheets stick together.

  • The total number of plates or sheets

  • that require a transformer saturation is defined,

  • then so be introduced until there

  • is no space to introduce one more.

  • To ensure a good fit between plate and sheet,

  • it usually is done by hitting with

  • a hammer.

  • Now will place the complement of the plate (E),

  • which are shaped plates (I),

  • these are interspersed in the gaps between

  • the backs of the plates (E).

  • Final adjustment of the plates

  • After installing all the plates,

  • we will fit together.

  • Place the transformer on a hard,

  • flat and let the hammer correcting its location,

  • until all the faces look perfectly flat.

  • Measurements

  • Series circuit

  • This system allows testing electrical circuits

  • without the risk of burning.

  • If the circuit is shorted,

  • the bulb turns on.

  • If the circuit is not shorted or open,

  • the bulb does not light.

  • Place the two alligators Circuit Series

  • at both ends of the transformer input current.

  • Series circuit must not ignite.

  • To verify that the windings are not open or interrupted,

  • rose along with the tips of the secondary winding

  • and the bulb will ignite.

  • Do the same with the tips of the additional winding.

  • If the windings are correct,

  • the light bulb in every case must turn on.

  • Now connect the transformer to the outlet.

  • With the multimeter on AC voltage scale,

  • place one end on the right end of the secondary winding

  • and the other in the central TAP.

  • You should mark the desired voltage,

  • in this case, 18 volts AC,

  • as well as between the left and Central TAP.

  • Measure between the two ends of the secondary winding.

  • You should mark twice, in this case 36 volts AC.

  • The additional winding must dial the desired voltage.

  • In this case between 12 and 13 volts AC.

  • Finishes

  • For aesthetics we recommend painting the plate

  • with an oil based paint.

  • So we get an optimal transformer

  • and good looking.

  • Plates bolted

  • To avoid vibration, crossed through bolts,

  • with nut and washer on the 2 top corners of the transformer

  • and squeeze very hard to get a solid piece.

  • In the two lower corners of the screws,

  • replacing washers per metal brackets.

  • These serve to hold the transformer

  • at the time of installation.

  • It is better to do than to buy.

  • Build your own transformers,

  • making sure of the product quality,

  • saving costs

  • and expanding your knowledge in electronics.

  • Success!

CONSTRUCTION A TRANSFORMER

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