Any EEs out there? Impedance question. | FerrariChat
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Any EEs out there? Impedance question.

Discussion in 'Technical Q&A' started by SoftwareDrone, Oct 31, 2013.

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  1. SoftwareDrone

    SoftwareDrone F1 Veteran
    Sponsor Owner

    Jan 19, 2004
    7,869
    San Jose, California
    Full Name:
    Mike
    #1 SoftwareDrone, Oct 31, 2013
    My company has a Protek B801 Sweep Function Generator. The output impedance is 50 Ohms. We need to send a signal (70 Hz sine wave) to a speaker and mount the speaker in front of a cassette full of semiconductor wafers to see if the signal will cause any of the wafers to creep out of the cassette. Thanks to SkidKid, I have an amplified subwoofer (10 inch) that I was thinking of using for this experiment. However, I do know that the speaker impedance is 8 Ohms nominal. I know the signal won't be going to the speaker directly (it will be going to the amp) but this is where I get lost real fast. I am a software engineer and NOT an electrical engineer, and I don't want to accidently blow up the subwoofer or fry the amp.
    Any help would be appreciated.
    :)
     
  2. rlips

    rlips Formula Junior

    Jul 29, 2011
    959
    New Jersey, USA
    #2 rlips, Oct 31, 2013
    If you are hooking the signal generator up to the amp, you are fine. Generally, a characteristic of an Audio amplifier would be a very high input impedance (greater than 50 Ohms) and a very low output impedance (much less than 8 ohms).

    The idea is the high input impedance will prevent your source from needing to source current into the amplifier, and the low output impedance ensures your amplifier can adequetly source enough current to drive the speaker. In this case, the signal generator will act as a voltage source, not a current source.

    It will be perfectly fine
     
  3. SoftwareDrone

    SoftwareDrone F1 Veteran
    Sponsor Owner

    Jan 19, 2004
    7,869
    San Jose, California
    Full Name:
    Mike
    #3 SoftwareDrone, Oct 31, 2013
    Well you are the MAN! :)
    Thank you.

     

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