HSC 2007 Q26 DC Transformer possible?? (1 Viewer)

[Mr_Kap]

In the HSC 2007 Q26(a).

"Explain why AC is preferable to DC as an input current for transformers"

Does this mean that there are DC transformers if they are asking this? What even?

And can someone help me answer this question as well. Thanks.

 

[sy37]

It is asking why AC > DC for transformers. It is because a transformer needs a changing magnetic flux so a current can be induced in the secondary coil. So AC is needed for this since.

 

[Fizzy_Cyst]

It is asking why AC > DC for transformers. It is because a transformer needs a changing magnetic flux so a current can be induced in the secondary coil. So AC is needed for this since.

Just be careful when saying DC cannot be used, as it is true that a TRUE or STEADY DC source cannot be used (constant positive voltage/current), whereas VARYING DC, which is somewhat similar to an absolute value sine graph (non-constant positive voltage/current) could be used as the voltage/current/flux is changing.

 

[mrpotatoed]

DC can also be used if you have a switch that is repeatedly opened and closed, as that would cause a changing flux. But obviously it is much easier / reliable and im assuming efficient to use AC.

 

[Fizzy_Cyst]

DC can also be used if you have a switch that is repeatedly opened and closed, as that would cause a changing flux. But obviously it is much easier / reliable and im assuming efficient to use AC.

Yep! Such 'switches' are termed 'interrupters' and are how induction coils function!

 

[Drsoccerball]

Yep! Such 'switches' are termed 'interrupters' and are how induction coils function!

Can transistors turn DC into variable DC?