Transformers, its current and its resistance

In summary, the conversation discusses the concept of power consumption in a transformer and how it is affected by different factors such as the type of device connected and the resistance in the transformer's circuit. The main question raised is how the power supply can consume more or less power from the home AC depending on the load of the connected device. The answer lies in the varying levels of resistance in the primary circuit caused by the consumption of power in the secondary circuit.
  • #1
Taturana
108
0
Hello,

Suppose a simple transformer, not connected to a circuit (just to the home AC). If we get a multimeter and measure its resistance we will get a number. So if we plug it into the home AC, it will consume energy (constant power).

Now suppose we have a desktop computer power supply. Well, the desktop consumption varies: if we are playing a game, the video card is dissipating more power etc. So, I would imagine that if the desktop consumption raises, the desktop is not only consuming more from the power supply, but the power supply is also consuming more from the home AC, otherwise it will be a really huge non-optimized solution for power supplies. But I also know that the only thing connected to the home AC (if we look the power supply circuit itself) is the transformer, which is, in essence, an inductor (but acts like a resistor, it's a lot of cable, it has a resistance).

Given this, the main question is: if the unique thing connected to the home AC is the coil of the transformer, and this coil has a resistance, which let's a I current flows, how could the power supply consume less or more power from the home AC?

I think you all understand my question. Please, could someone give me a clear explanation on that?

Thank you very much
 
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  • #2
I can't do a detailed explanation as I don't know enough, but I believe that the different items that are consuming power in the secondary windings circuit cause various levels of resistance in the primary circuit through counter EMF.
 

Related to Transformers, its current and its resistance

1. What is the concept of "transformers"?

Transformers are electrical devices that are used to transfer energy between two or more circuits through electromagnetic induction. They consist of two or more coils of wire, known as the primary and secondary windings, that are wrapped around a common core. The primary winding receives energy from an alternating current, which produces a changing magnetic field. This changing magnetic field then induces a voltage in the secondary winding, allowing the energy to be transferred to the secondary circuit.

2. How do transformers work?

Transformers work on the principle of electromagnetic induction. When an alternating current flows through the primary winding, it creates a changing magnetic field around the core. This changing magnetic field then induces a voltage in the secondary winding, causing an alternating current to flow in the secondary circuit. The ratio of the number of turns in the primary and secondary windings determines the voltage and current levels in the secondary circuit.

3. What is the purpose of current and voltage transformation in transformers?

The main purpose of transformers is to transfer electrical energy between two circuits. The transformation of current and voltage in a transformer allows for efficient transmission and distribution of electricity over long distances. It also allows for the step-up or step-down of voltage levels to meet the specific needs of different electrical devices and systems.

4. What is the role of resistance in transformers?

Resistance in transformers is an important factor in determining the efficiency of energy transfer. A transformer with low resistance will have less energy loss, resulting in higher efficiency. High resistance can lead to energy loss in the form of heat, reducing the transformer's efficiency. Therefore, transformers are designed with materials that have low resistance to minimize energy loss.

5. How are transformers used in everyday life?

Transformers play a crucial role in our daily lives, providing a means of supplying electricity to homes and powering various electrical devices. They are used in power plants to step up the voltage for long-distance transmission and then stepped down for distribution to households. Transformers are also used in electronic devices, such as chargers, to convert high-voltage electricity to lower levels suitable for charging batteries. They are also used in appliances like refrigerators, televisions, and air conditioners to step down the voltage for safe use in homes.

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