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  1. R

    Help with pnp BJT amplifier circuit

    I don't know what that book defines as applicable to the "voltage divider rule".. I always thought that a load not less that 10 times the resistance of the divider resistor was recommended. The load is 3k times beta = 300k . Therefore, R2 should not be greater than 300k/10 = 30K. To keep the...
  2. R

    Diode question

    That Kirchoff loop equation which includes the diode equation does not have a closed form solution. It is of the same ilk as Cos(x) = x , where x is in radians. Those kind of equations have to be solved by numerical approximation methods involving a lot of arithmetic work. Best to let the...
  3. R

    Diode question

    Equation solvers are all over the IoT. https://www.symbolab.com/solver/equation-calculator Ratch
  4. R

    Diode question

    You can solve that problem algebraically or graphically with a load line. Write the equation as-- The diode equation is-- Assuming Io is 1E-11, we solve for Vd Assuming a 1.25 ohm resistor, and 1 volt across both the diode and resistor, we can calculate the current using the first equation...
  5. R

    Phase and frequency

    You tell me. The sin waves below have a frequency of 3 and 5 hertz respectively. They are plotted for one second. Are they in phase at 0.0, 0.5, and 1.0 secs.? Ratch
  6. R

    OR-ing voltages together

    It appears you want a mixer. Try this circuit. http://electronicdesign.com/ideas-design/efficiently-design-op-amp-summer-circuit Ratch
  7. R

    50Hz sine wave

    First you ask about generating a wave, then you ask about inputting a wave. Which is it? Do you mean signal level or power level? Be more specific. Ratch
  8. R

    Electronic book exercise

    I found in Sedra, edition 6, a statement that confirms the size means the junction area "Since Is is directly proportional to the junction area (i.e., the device size)...". I note that in the beta=100 BJT, the diode junctions Db and De are one and the same diodes. Same with the beta=1000 BJT...
  9. R

    Electronic book exercise

    I looked through the English versions of the 3, 5, and 6 editions of MicroElectronic Circuits. I did not see any problems that combine diodes and BJTs like your translation shows. I assume that your chapter is named "Diodes", right? Your translation says "dimensions", but does it really mean...
  10. R

    rms value of current

    If the book says the RMS for a 5 amp peak is 0.3535, then it is wrong. The correct RMS value is 3.536. Why are you using the RMS value to calculate the average current. You should use the peak value to get the correct answer. Ratch
  11. R

    Parallel Circuit with current source and dependent current source. HELP!

    What is the above group of equations supposed to represent? Do you know the principles of node evaluation? If so, then apply it. Ratch
  12. R

    Electronic book exercise

    Could you give the exact name of the book, the edition level, and the page where this problem can be found? Ratch
  13. R

    Woo-Woo Energy loss In a circuit?

    My rebuttals are timeless. Ratch
  14. R

    Woo-Woo Energy loss In a circuit?

    That means no such thing. You always get less machine work than the amount of heat energy you input. Wait a minute. You said the system was closed. How does energy escape from a closed system? No it wasn't. They are independent of each other. Show us where or how that happens. I infer...
  15. R

    Woo-Woo Energy loss In a circuit?

    What does the origin of something have to do with modifying it? What does it matter who "states" the physical laws, as long as they are correct? Ideas have nothing to do with laws, and neither does opposition to laws. Physical laws are the defining relationship of quantities and forces in...
  16. R

    Woo-Woo Energy loss In a circuit?

    Changing perspective might lead to better understanding of something, but it does not change what is possible or not. The opportunities are nil because that kind of machine is not possible. You hopes will be dashed. Ratch
  17. R

    Woo-Woo Energy loss In a circuit?

    Be specific, who was they? Was it folks informed about the limitations of current technology, who made a prediction of what was possible with what was available at the time? Some things are indeed impossible, such violating the laws of physics. You are confusing difficult applied engineering...
  18. R

    Woo-Woo Energy loss In a circuit?

    What do you mean by "mass energy loss"? Do you mean massive energy loss? Or loss of mass from a nuclear reaction as shown by Einstein's E=m*c ^2? Maybe the potential or kinetic loss of a mass of something? What? Ratch
  19. R

    Parallel Circuit with current source and dependent current source. HELP!

    Just slogging through one node analysis problem is not going to teach you node analysis. Have you actually studied the principles that make that method work? I think you need more instruction in circuit theory. If you have difficulty with this simple problem, you are not going be able to do...
  20. R

    Parallel Circuit with current source and dependent current source. HELP!

    It is a simple problem in node analysis. Do you know how to do node analysis? It looks like you are making hard work of it. Ratch
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