Inductive interference from two EM coils (aka a transformer)

In summary, the conversation discusses the power consumption of electronic devices and whether turning them off completely has any impact on the power drawn from the source. It is mentioned that the source coil in the transformer is a simple inductor and the other coil induces an electric current, which does not affect the current drained from the source. The conversation concludes with the question of whether turning off a laptop computer has any significant impact.
  • #1
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I've been wondering about this for a long time.

The little black box that you plug into the wall so you can power your electronic devices contains a general run-of-the-mill transformer.

But if the power is completely shut off to the device: not draining any current waiting for a power button to be pressed, or even unplugged from the device end so the cord is left dangling; then shouldn't the power consumption from the source (the power company's electric meter) be the same as if it were drawing the maximum that this device possibly could?

The source coil in the transformer is a simple inductor. It provides a load (resistance from the coil) which is converted to (marginal) heat and a magnetic field. The other coil induces an electric current (and a bit more heat) from the alternating magnetic field.

Whether or not that other coil uses that induced current shouldn't affect the current drained from the source, right? I mean the entire circuit of the device could be replaced with a theoretical metal plate representing the resistance of the entire circtuit (reactance and impedance not applying after AC->DC conversion takes place). Now, I don't see how drain to source inductance can make any printed circuit or conglomerate of wires or whatever induce a voltage in the source and stop the source coil from being a straight (-) ---v^v^--- (+) circuit. (that's a resitor)So there's really no point in turning my laptop computer off, right?
 
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  • #2
That doesn't help at all.
 

What is inductive interference from two EM coils?

Inductive interference from two EM coils, also known as a transformer, is a phenomenon in which an alternating current in one coil produces an alternating magnetic field, which then induces a current in a nearby coil.

How does a transformer work?

A transformer is made up of two coils, a primary coil and a secondary coil, that are wound around a core. When an alternating current passes through the primary coil, it produces a changing magnetic field that induces a current in the secondary coil, resulting in the transfer of energy from one coil to the other.

What are the main applications of transformers?

Transformers are commonly used in power distribution systems to step up or step down the voltage of electricity, making it easier to transmit over long distances. They are also used in electronic devices to convert AC voltage to DC voltage and to isolate circuits from each other.

What factors affect the efficiency of a transformer?

The efficiency of a transformer depends on factors such as the type of core material, the number of turns in each coil, and the quality of the insulation. Higher quality core materials and more turns in the coils can result in a more efficient transformer.

What are the safety precautions for working with transformers?

When working with transformers, it is important to follow proper safety precautions to avoid electric shock. This includes wearing protective gear, de-energizing the transformer before working on it, and ensuring proper grounding and insulation. It is also important to be aware of the potential hazards of high voltage and to handle transformers with care.

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