Electronics Questions: Difference between revisions

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'''Chapter 1'''
'''Chapter 1'''
*20,1,3: Shouldn't the output voltage get larger as <math>R_L</math> gets smaller?
*Page 20, Line 3.
:* No.<math>R_O</math> is in series with <math>R_L</math>, so if <math>R_L</math> gets smaller, there will be a smaller voltage drop over <math>R_L</math> and a larger voltage drop over <math>R_O</math>
*21, F1.18: Why does it have to have an source impedance? How big is this impedance? Loading effects? Could we get rid of this if we had superconducting wires?
:* The source impedance is simply to reflect the real world internal losses of the system. If you want to use these models, you will need to make a Thevenin or Norton equivalent.
:* When you make the Thevnin or Norton equivalent of a circuit, you will find out how big these impedances are.
:* Loading effects are the impedances that reduce the voltage or current to the intended source. For F1.18, these are <math> R_s</math> and <math>R_o</math>, for F1.28, it is <math>R_o</math>
:* Yes! It depends on what part of the project you get to design. If you get to work on the pre-amplifier section, you can have small resistances (for a Thevenin equivalent) or high resistances (for a Norton equivalent). If you are designing the amplifier section, you can stick in a buffer amplifier in so that there is no voltage drop (due to no current) flowing into the amplifier. This ensures the voltage drop is completely across the load/input resistor.
*31, F1.25: Why are the output resistances placed where they are? It seems there would be a voltage drop over the voltage amplifier and extra current not being accounted for in the current amplifier?
:* The resistor is there because it is a Norton equivalent. Loading effects will play a part, but if you are designing this section of the amplifier, your design can take this into account to provide minimum losses.
*If <math>V_{BE}</math> is 0, and <math>V_{CE}</math> is very large, will you get any current flow?
*1/22/2010,3: Explain the protection diode so that the transistor doesn't arc over.
*Capacitor_L acts like an open circuit for DC and a short circuit for AC
*AC coupling goes through a blocking capacitor, while DC coupling doesn't
*How is the BJT amplifier an inverting amplifier?

Latest revision as of 16:05, 28 January 2010

Format: Page, Paragraph, Line.

Chapter 1

  • 20,1,3: Shouldn't the output voltage get larger as gets smaller?
  • No. is in series with , so if gets smaller, there will be a smaller voltage drop over and a larger voltage drop over
  • 21, F1.18: Why does it have to have an source impedance? How big is this impedance? Loading effects? Could we get rid of this if we had superconducting wires?
  • The source impedance is simply to reflect the real world internal losses of the system. If you want to use these models, you will need to make a Thevenin or Norton equivalent.
  • When you make the Thevnin or Norton equivalent of a circuit, you will find out how big these impedances are.
  • Loading effects are the impedances that reduce the voltage or current to the intended source. For F1.18, these are and , for F1.28, it is
  • Yes! It depends on what part of the project you get to design. If you get to work on the pre-amplifier section, you can have small resistances (for a Thevenin equivalent) or high resistances (for a Norton equivalent). If you are designing the amplifier section, you can stick in a buffer amplifier in so that there is no voltage drop (due to no current) flowing into the amplifier. This ensures the voltage drop is completely across the load/input resistor.
  • 31, F1.25: Why are the output resistances placed where they are? It seems there would be a voltage drop over the voltage amplifier and extra current not being accounted for in the current amplifier?
  • The resistor is there because it is a Norton equivalent. Loading effects will play a part, but if you are designing this section of the amplifier, your design can take this into account to provide minimum losses.
  • If is 0, and is very large, will you get any current flow?
  • 1/22/2010,3: Explain the protection diode so that the transistor doesn't arc over.
  • Capacitor_L acts like an open circuit for DC and a short circuit for AC
  • AC coupling goes through a blocking capacitor, while DC coupling doesn't
  • How is the BJT amplifier an inverting amplifier?