So essentially a resistor eats up/throws away energy?

  • Thread starter vmars
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Main Question or Discussion Point

I understand that a resistor can lower current flow at the expense of heat.
So essentially a resistor eats up/throws away energy?
Isn't there a better way to change current flow without throwing away energy?
Thanks!
...Vern
 

Answers and Replies

  • #2
Defennder
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Use a voltage source of lower voltage?
 
  • #3
NoTime
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I understand that a resistor can lower current flow at the expense of heat.
So essentially a resistor eats up/throws away energy?
Isn't there a better way to change current flow without throwing away energy?
Thanks!
...Vern
Yep, resistors turn energy into heat.

Sometimes the desired result is heat, say a toaster or room heater, so saying that energy is thrown away is incorrect.

In other cases a resistor can reduce the total energy consumed, so you have to look at the big picture.

In some cases alternate methods are used, for example switching power supplies.
 
  • #4
Isn't there a better way to change current flow without throwing away energy?
You can also use transistors to affect current flow. You'll still have power dissipated, though.
 
  • #5
turbo
Gold Member
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It is also possible that a resistor (or several of them) will supply a load to a power supply such that that power supply can supply a regulated drain instead of appearing like a high drain or a dead short.
 

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