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.