Network transformers from electric motors. Scheme, description

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Schemes of radio-electronic and electrical devices

Network transformers from electric motors. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Electric motors

Comments on the article

A failed electric motor can not always be restored. Low-power electric motors contain a large number of turns of their windings, wound with a thin wire. This complicates their rewinding. In many cases, it is easier and cheaper to replace such an electric motor with a new one than to engage in the laborious process of rewinding burnt windings. But do not rush to throw away the burned-out electric motor. I already have transformers wound on the cores of former electric motors in several power supplies.

To make a transformer, it is necessary to remove the old windings and wind new ones. New windings are wound using a shuttle, which is used when winding toroidal transformers.

Before winding, it is necessary to cover the magnetic circuit with a layer of some kind of good insulation. Even the most ordinary electrical tape will do if the transformer does not overheat. To prevent the transformer from overheating, there is no need to rush to wind the secondary windings. First, the transformer is left connected to the network for 8 ... 12 hours under the vigilant control of its operation.

If the windings barely noticeably warm up, then you can start winding the secondary windings. Otherwise, the primary winding must be winded. If it is difficult or impossible to keep your hand on the transformer for a long time, then with a load on the secondary windings, overheating of the transformer is more than likely. Overheating leads to insulation defects between the turns of the windings, short circuits between the latter and failure of the transformer.

The transformer can overheat for several reasons: 1) too small overall power of the magnetic circuit (low-power core); 2) insufficient section of the winding wires; 3) an unacceptably small number of turns of the primary winding; 4) bad iron. They don’t write about the latter, but it’s not “exotic”! If we use electric motor steel as iron, then the number of turns has to be increased in relation to good transformer steel.

The stray field of a transformer wound on a steel core of an electric motor is somewhat uneven and larger than that of a conventional toroidal transformer. This is due to the fact that the shape of the core is different from the toroidal one. Because of this, the windings are placed unevenly. But the interference emitted by such transformers is much less than that of the widely used TS-180, TS-200, TS-270, etc.

As you know, the cores of powerful electric motors are used for the manufacture of electric welding machines. Engines with a power of tens or hundreds of watts remain unclaimed. Most of all, powerful collector motors from old meat grinders, etc. are suitable for making transformers.

Having dismantled the case of such a "combine", we have access directly to the iron of the engine, without any covers, metal "sarcophagi", etc. Naturally, we are talking about an engine that cannot be restored.

Now most electric motors are rewound in workshops. But an operation of this kind can be more expensive than buying a new engine. In addition, unqualified rewinding often leads to repeated repairs. So the probability of a defective electric motor appearing in the arsenal of an amateur is quite high.

Determination of the optimal number of turns of the primary winding can be carried out according to the method [1].

References:

Zyzyuk A.G. About transformers // Radioamator. - 1998. - No. 2. - P.38.

Author: A.G. Zyzyuk

See other articles Section Electric motors.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Air trap for insects 01.05.2024

Agriculture is one of the key sectors of the economy, and pest control is an integral part of this process. A team of scientists from the Indian Council of Agricultural Research-Central Potato Research Institute (ICAR-CPRI), Shimla, has come up with an innovative solution to this problem - a wind-powered insect air trap. This device addresses the shortcomings of traditional pest control methods by providing real-time insect population data. The trap is powered entirely by wind energy, making it an environmentally friendly solution that requires no power. Its unique design allows monitoring of both harmful and beneficial insects, providing a complete overview of the population in any agricultural area. “By assessing target pests at the right time, we can take necessary measures to control both pests and diseases,” says Kapil ... >>

The threat of space debris to the Earth's magnetic field 01.05.2024

More and more often we hear about an increase in the amount of space debris surrounding our planet. However, it is not only active satellites and spacecraft that contribute to this problem, but also debris from old missions. The growing number of satellites launched by companies like SpaceX creates not only opportunities for the development of the Internet, but also serious threats to space security. Experts are now turning their attention to the potential implications for the Earth's magnetic field. Dr. Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics emphasizes that companies are rapidly deploying satellite constellations, and the number of satellites could grow to 100 in the next decade. The rapid development of these cosmic armadas of satellites can lead to contamination of the Earth's plasma environment with dangerous debris and a threat to the stability of the magnetosphere. Metal debris from used rockets can disrupt the ionosphere and magnetosphere. Both of these systems play a key role in protecting the atmosphere and maintaining ... >>

Solidification of bulk substances 30.04.2024

There are quite a few mysteries in the world of science, and one of them is the strange behavior of bulk materials. They may behave like a solid but suddenly turn into a flowing liquid. This phenomenon has attracted the attention of many researchers, and we may finally be getting closer to solving this mystery. Imagine sand in an hourglass. It usually flows freely, but in some cases its particles begin to get stuck, turning from a liquid to a solid. This transition has important implications for many areas, from drug production to construction. Researchers from the USA have attempted to describe this phenomenon and come closer to understanding it. In the study, the scientists conducted simulations in the laboratory using data from bags of polystyrene beads. They found that the vibrations within these sets had specific frequencies, meaning that only certain types of vibrations could travel through the material. Received ... >>

Random news from the Archive

Traces of the first Europeans 18.11.2003

On the western slope of the extinct volcano Roccamonfina, 50 kilometers from Naples, archaeologists from the University of Padua discovered traces of three human beings left 325-385 thousand years ago.

They were representatives of the "upright man" species. Their growth is estimated at one and a half meters, foot size - 34th. The distant ancestors of Europeans, descending from the mountain, walked along a layer of volcanic ash, which later petrified, preserving footprints. One of the walkers slipped and left a handprint on the ashes. These are the oldest human footprints in the world, and the oldest hominin footprints are found in Tanzania - they are about 3,5 million years old.

It is curious that the locals, having known these footprints for a long time, considered them to be the footprints of the devil: who else can walk along the volcano, leaving prints in the stone?

Other interesting news:

▪ Sound stream localization creates the perfect signal

▪ Wide-gap semiconductors for automobiles

▪ Bones grow from fish scales

▪ The tablet makes a diagnosis

▪ Tests of the suborbital space plane SpaceShipTwo

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ site section Power supplies. Article selection

▪ article by Anatole France. Famous aphorisms

▪ article Where Does the Wind Come From? Detailed answer

▪ article The operator of the smoke plant. Job description

▪ article Low power chargers. Encyclopedia of radio electronics and electrical engineering

▪ article Electrical installations in hazardous areas. Application area. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews