Why did the fuse blow when a DC supply was connected to a transformer?

In summary, the conversation discusses the accidental use of a DC supply on a transformer in a college lab, resulting in a blown fuse. It is explained that transformers typically work with AC voltage and that for DC voltage, they act like a short wire with low resistance. The speaker also suggests that the person asking for an explanation should already know the answer if they are working with transformers in a lab. It is also mentioned that the transformer's iron core acts like an electromagnet and produces a back emf which delays the increase of DC current, leading to the blown fuse.
  • #1
dhivakhar
4
0
my friend gave a dc supply to a transformer in my college lab accidentally and the fuse went off can i get an explanation on why this happened?
 
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  • #2
Transformer work only with AC voltage. For DC transformer act just like a short wire (a very small resistance ).
 
  • #3
Jony130 said:
Transformer work only with AC voltage. For DC transformer act just like a short wire (a very small resistance ).
Can you please explain how a transformer shows very small resistance to a DC supply?
 
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  • #4
Actually this sounds like a disguised homework question. If you are messing with transformers in lab you should already know the answer to the question.
 
  • #5
Because transformers is essentially just two or more coils of wire wrapped around the core. And wires has "low" resistance.
 
  • #6
dhivakhar said:
my friend gave a dc supply to a transformer in my college lab accidentally and the fuse went off can i get an explanation on why this happened?
You have a careful smart friend
 
  • #7
Actually, if your friend had been able to measure the way the current varied around the time of switch on, he would have found that the current value followed a curve, because the Iron core of the transformer behaves like an electromagnet. The magnetic field energy takes time to build up and it produces a 'back emf' which delays the DC current increase (This would be fairly quick with a mains transformer - only a few tens of milliseconds before the fuse started to blow.)
 

1. How does a DC supply provide power to a transformer?

A DC supply is an electrical circuit that delivers a constant, unidirectional flow of electrical energy. When connected to a transformer, the DC supply provides a continuous source of power that is converted into AC energy by the transformer.

2. What is the role of a transformer in a DC supply circuit?

A transformer is a device that can increase or decrease the voltage of an electrical signal. In a DC supply circuit, a transformer is used to convert the DC energy into AC energy, which can then be used to power various electrical devices.

3. Can a DC supply be used to power all types of transformers?

No, not all transformers can be powered by a DC supply. Some transformers are specifically designed to work with AC power sources, and attempting to use a DC supply could damage the transformer or result in inefficient power conversion.

4. What are the advantages of using a DC supply over an AC supply for a transformer?

One advantage of using a DC supply is that it eliminates the need for a rectifier, which is typically required to convert AC power to DC power. This can simplify the circuit and reduce costs. Additionally, DC supplies can be more efficient and provide a more stable source of power compared to AC supplies.

5. Are there any safety considerations when using a DC supply with a transformer?

Yes, it is important to follow proper safety precautions when working with a DC supply and transformer. Make sure to use the correct voltage and amperage ratings for the transformer, and follow all manufacturer instructions. It is also important to use proper insulation and protective gear when handling electrical components.

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