Calculate characteristics and the number of turns of the future step-down transformer. To do this, find out the voltage in the primary network, the voltage you want to output, and the cross-sectional area of the core. So, if you are planning out voltage 220 B to 12 B in cross-sectional area of 6 sq cm, then you need a constant value for the average transformer iron, which equals 60, divided by the area. Get that for each Volt represents 10 turns. Multiply this by 220 and the result is the number of turns of the primary winding. The secondary winding is calculated as: 10 turns multiply by 12 Volts.
Take the lead, which is present in silk or cotton insulation. Section select small, about 0.3 mm. To locate the secondary winding wire cross-section 1 mm. Stock up on tinplates for the manufacture of the core. To do this, take the cans and cut them about 80 strips of width 2 cm and length of 27-30 cm Otoshita them in the oven and allow to cool, then clean off the scale, cover them with varnish and paste over one side of thin paper.
Make the frame for the coil. It can be made from thick cardboard. Pre-wrap it in several layers of paper preparativnoi. Then start winding the wire. Ensure that after two or three rows of laid paper. The ends of the primary winding clip to the frame and lay several more rows preparational paper.
The secondary winding route in the same direction as the primary. Don't forget the insights you need to make 120 and 240 turns (by calculation). Insert the iron strips in the finished coil that should be half its length. They go around the frame with one hand and connect at the bottom. Leave between the core and the frame of the air gap.
Make the base of the transformer. To do this, take a small Board with a thickness of about 5 cm, fasten with metal braces that wrap around the lower part of the core. Print on the frame the ends of the windings and secure them to the contacts.
Advice 2: How to make a Tesla coil
One of the most famous electric devices created by the genius scientist Nicola Tesla in the late nineteenth century, is a high-voltage resonant transformer (Tesla coil). Produced transformervoltage ohms the high frequency potential of several million volts leads to the appearance in the air of large and colorful electric discharges. A hundred years of existence, the device is overgrown with legends and myths. But today, anyone can make transformer Tesla and to make sure natural created effects.
You will need
- - a thin copper wire;
- - thick copper wire or copper tube;
- - step-up transformer (from 220 to ~1500 volts);
- high voltage ceramic capacitor;
- epoxy or varnish;
- - electrical tape or silk fabric;
- - massive electrode spark gap;
- - aluminum foil or aluminum corrugated pipe.
Fabricate secondary coil transformerand Tesla. Wrap 1-1.5 thousand turns of thin copper wire on the frame from dielectric. The coil must be very good insulation, both external and inter-turn. The isolation coil may be performed by coating epoxy resin or varnish, wrapping the silk cloth impregnated with varnish, or several layers of insulating tape. As a skeleton you can use a piece of plastic tubing with a diameter of 5-6 centimeters. From different sides of the coil draw conclusions thick wire with good insulation. One for providing the ground and the other to connect to the end discharger.
Create a primary coil transformerand Tesla. Bend a copper pipe, thick copper wire or bus in the shape of a spring with a diameter of 9-12 inches. Slightly stretch the spring." Coil of wire should have five or six turns and insights to connect it with other parts of the device.
Make a discharger. Massive metal electrodes attach to the base of the dielectric (e.g., thick fiberglass). Provide the possibility of adjusting the distance between the electrodes.
Make transformer Tesla. On the base of dielectric material vertically secure the primary and secondary windings. The secondary winding of the lower part should be inside the primary. On top of the frame of the secondary winding install the arrester in the form of a ball or toroid. Connect one end of the winding. The ball can be made of foil, the toroid - aluminum corrugated tube. The second end of the secondary winding securely ground. Connect the high-voltage capacitor to one terminal of the primary winding and one of the contacts of the arrester. Free contact spark plug to a free output of the primary winding. The terminals of the secondary winding increases the supply transformerand connect to the contacts of the spark gap. The simplest transformer Tesla is ready.
Be careful when testing of the Tesla transformer. Though its maximum output power is small, and short-term discharge does not cause serious damage, careless handling can cause injury. Direct contact with discharge may cause skin burns. Long exposure of high-frequency currents on the body due to stay in the immediate vicinity of the source discharges, which can disrupt biochemical processes in the skin and cause various diseases.
Advice 3: How to connect step-down transformer
Step-down transformer designed to power loads less stress than that which is available in the network. So it is not out of order, you must find and correctly connected to the coil, which is designed for this purpose.
You will need
- The transformer, voltmeter, tools.
We should not think that network winding of the power transformerand is always that which has the maximum resistance, or the greatest number of turns. There are so-called anode-filament transformers in the set of windings which are decreasing and increasing. However, if it is known that the transformer is step-down only, feel free to take the high resistance of the windings over the network.
When it is unknown whether all of the secondary winding are lower, consider the following hallmarks of primary winding: its conclusions are located at some distance from the rest, or it is wound in separate sections of the frame.
When in doubt, take a picture of the transformer, and then put the profile in the forum, do not forget to specify the brand of the device. You will soon receive information about the location of insights. Also make sure that the transformer is designed for voltage 220 V and frequency 50 Hz (there are 400-Hz, which at low frequency instantly burn out).
If the power winding has three leads, one of them is a tap to enable the 110 or 127 volt network. Find this combination of conclusions of the coil at which the maximum resistance is obtained - that they can be fed with 220 V. If the findings are not three, but four, it is usually a question of two separate windings which are to power from 220-volt mains must be connected not only sequentially, but also in phase.
Searching for the right way in-phase connection of the windings, connect them in series, connect to AC voltmeter, working at the limit of 500 V, then, without referring to the conclusions of the primary windings, one secondary feed AC voltage of several volts. Read the voltmeter, then disconnect the voltage, reverse the findings of one of their primary windings and repeat the experience, then remove the voltage. Option for maximum voltmeter readings and is correct.
Now, knowing the location of the primary winding (or windings of the two) connect it (either two windings in series and in phase) to the network via a fuse, the rated current of which select depending on the power transformera (0.05 A per 10 watts). Then carefully, without touching any of the leads (secondary winding can also be high voltage!), measure with a voltmeter variable voltage produced by the transformerohms.
To get from AC to DC, connect to the secondary winding of the rectifier with a filter. Observe polarity when connecting the output of the bridge to the electrolytic capacitor. Note that the voltage at the output of the filter will increase 1.41 times compared to the current value of the voltage on the secondary winding.
All perepiski engage when de-energized the transformere, and if the rectifiers high voltage before touching the parts, not only obestochivaete transformer, but also discharges the capacitors of filters. Do not exceed the maximum currents of the individual windings and the total power consumed by the transformerand as a whole.