Potentiometer Orientation Question

Discussion in 'General Electronics Chat' started by tracecom, Jun 2, 2012.

  1. tracecom

    Thread Starter AAC Fanatic!

    Apr 16, 2010
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    In the attached schematic, is the input signal maximized with the pot adjusted for maximum resistance between the wiper and ground?

    Thanks.
     
  2. MrChips

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    Oct 2, 2009
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    The pot is wired as a voltage divider. Yes, the signal transferred is maximum when the wiper is moved away from GND.
     
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  3. tracecom

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    Thanks. Now, I have another question. Pin 8 of the TDA1517 is a mute/standby switch, which mutes the output when the pin is low. What is the advantage of using that feature as opposed to simply switching the power off to pin 7?
     
  4. #12

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    Using the mute command eliminates going through a re-start which often comes with transients (thumps in the speaker).
     
  5. tracecom

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    Thanks. That was my guess, but I didn't know for sure. I have noticed that the first time I operate the switch, there is only a very little pop from the speakers, but if I mute the amp and then immediately unmute it, there is more of a pop. Is there a way to eliminate the pop altogether?
     
  6. #12

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    Page one of the datasheet says, "No switch on/switch off plop".
    This is going to require somebody that actually knows this chip, and it isn't me.
     
  7. tracecom

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    In comparing the MK190 schematic (attached to my first post) to the application diagram in the TDA1517 datasheet, there are two differences.

    One is that the filter cap on the power input is 2200 μF in the datasheet and only 1000 μF in the MK190.

    The second is that the small cap on the power input is 100 nF in the datasheet and 220 nF in the MK190.

    The third is that the datasheet does not show pin 8 connected to ground at any time, however the MK190 shows it connected to ground when it is not connected to pin 8.

    Are any of these differences significant, expecially as it relates to the pop at power-on?
     
  8. #12

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    Now that you have completely changed the goal, perhaps a new thread is in order.
     
  9. tracecom

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    Last edited: Jun 2, 2012
  10. Audioguru

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    You already have too many threads about your amplifier.
     
  11. tracecom

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    I suppose you are entitled to that opinion, however yours is the first post in this thread in two and a half months.
     
  12. Audioguru

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    Dec 20, 2007
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    I don't look at dates.
    Maybe a Spammer made me have an e-mail of a new post.
     
  13. #12

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    I often get sucked into answering a necropost because I forget to check the date. :(
     
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