3-5watts?

Discussion in 'The Projects Forum' started by cloud18, Sep 15, 2011.

  1. cloud18

    Thread Starter New Member

    Sep 6, 2011
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  2. Wendy

    Moderator

    Mar 24, 2008
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    Are you wanting to measure total wattage of the circuit, or output power?

    For total wattage of the circuit you measure the current, then the power supply voltage.

    P = V * I
     
  3. cloud18

    Thread Starter New Member

    Sep 6, 2011
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    It will be helpful if both.
    I know the formula of the Power, but what I am after is to where in the circuit and how will I connect my WATTMETER?
    Because I tried connecting and simulating it on the output part and it reads ---.--uW.
     
  4. t_n_k

    AAC Fanatic!

    Mar 6, 2009
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    You would interpose the wattmeter between the amplifier output and a purely resistive dummy load which replaces the speaker - it might be 8Ω. You would have to inject a suitable signal at the amplifier input. The input signal level (say using a 1kHz pure sine wave source) would be increased until the power output was as expected, but not at a level where unacceptable distortion of the amplified version of the input signal is observed at the load. So you would need to assess the output signal quality (harmonic distortion) to make this a genuine test of output power performance.
     
  5. #12

    Expert

    Nov 30, 2010
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    You also need to be sure your wattmeter works properly at the frequency you are measuring. A Kill-A-Watt meter for appliances will not measure (most) audio frequencies.
     
  6. cloud18

    Thread Starter New Member

    Sep 6, 2011
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    What will be the WATTAGE of the speaker?
     
  7. wayneh

    Expert

    Sep 9, 2010
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    3,061
    Stick the whole thing inside a calorimeter and measure heat production. ;)
     
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