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Is op amp or any amplifier circuit/device a over-unity device?

  1. Jan 20, 2011 #1
    Is op amp or any amplifier circuit/device a over-unity efficient device?

    The above question has been stuck in my mind, and I can't figure it out, as Vout is greater than Vin which Pin>Pout. So is it?

    I heard alot about free energy and aether, thus come to this question.
  2. jcsd
  3. Jan 21, 2011 #2
    Do you mean over 100% efficiency? Absolutely not. If there is one, I want one too!!!:rofl:

    Or are you just talking about voltage gain?
  4. Jan 21, 2011 #3
    the efficiency. So how to calculate its efficiency, if it is not Vout/Vin since it is voltage gain?
  5. Jan 21, 2011 #4
    I am confuse how do you define efficiency? I am confused. To me, efficiency means power out divid by power in times 100 percent. Nothing even come close to 100%. Power in include the driving power plus the power input from the power supplies.
  6. Jan 21, 2011 #5
    So power in should be the Voltage IN while power out should be Voltage OUT? I am confused how to calculate it. Maybe although the voltage gain is high, the output current is very low? I do know that is true for transformers, but dunno for any opamp or semiconductor.
  7. Jan 21, 2011 #6


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    Staff: Mentor

    I will put this as gently as I can.

    The big giant battery or the wall power plug is where the "extra" energy comes from for power amplifiers. There is no free energy.

    Thread closed. Please re-read the Rules link at the top of the page that you agreed to when you joined our forums.
  8. Jan 21, 2011 #7


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    Staff: Mentor

    Just to add one thing: voltage is not power. Wattage is power.
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