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Finding total circuit current consumption for BJT amp

  1. Apr 25, 2013 #1
    For a common base bjt amp, would I be correct in thinking that to measure total power consumed by the circuit, you would measure voltage from Rc down to Re (inclusive) and take a current measurement from between Vcc and Rc and then multiply together?
     
  2. jcsd
  3. Apr 25, 2013 #2

    berkeman

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    Staff: Mentor

    It may depend on how you draw the circuit, and how you bias it. In this configuration below, the current consumption from the power supply should be pretty apparent:

    http://autonopedia.org/wp-content/uploads/crafts-and-technology/electronics/Common_base.png

    http://autonopedia.org/wp-content/uploads/crafts-and-technology/electronics/Common_base.png
     
  4. Apr 30, 2013 #3
    The easiest way to measure it is to put a small sense resistor in the power supply connection (where small here means small enough to make the IR drop not an issue). Then you can calculate the current consumption from Ohm's law.
     
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