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  1. R

    Gain of operational amplifier...

    The ability of the opamp to supply the current is not the problem. If 1 mv is applied to the input and R2 is 0.1 ohm, then 10 ma of current will have to be supplied by the opamp via R1. That makes 100 volts across R1. Of course the opamp will hit and stick at the voltage rail long before...
  2. R

    Gain of operational amplifier...

    If R2 is very low or close to zero, the large current supplied by R1 will lock up the circuit to the positive rail voltage as fast as the slew rate can take it there. Ratch
  3. R

    Beginning electronics, understanding whats actually happening

    What is your problem? There is a multitude of books and web resources that teach and explain electrical science, both theory and hardware. Why do you have a hard time understanding what is taught? Others have learned it, why can't you? Can you learn other subjects? Do you have a hard time...
  4. R

    Gain of operational amplifier...

    No. No. AC or DC gain? Assuming DC gain is of interest, the input resistance at point 2 is in the multi megohm range. Therefore the relatively small resistance of 1 kilohm is not going to affect the voltage from point 1 very much. So, 1 mv applied at point 1 will be 1 mv at both points 2...
  5. R

    Volts per metre

    Another way to detect an electric field is to measure the force on a charged particle (electron, proton) when the particle encounters an electric field. That is how some CRTs deflect the electron beam. Volts per meter and force per charge both reduce to the same units. I can show you how to...
  6. R

    Reducing variable voltage

    It would be nice to know for sure whether you are referring to AC or DC. Ratch
  7. R

    Hello can somebody tell me please collector capacitor

    Yes, it is wrong, as are so many articles on how capacitors work. Anytime you hear someone saying a capacitor or battery being "charged", that is wrong. The battery does not transport charge from one plate to the other. The capacitor separates charge by accumulating charge carriers on one...
  8. R

    Hello can somebody tell me please collector capacitor

    No, capacitors store energy, not charge. A capacitor energized to 1000 volts contains the same net charge as one with no voltage across it. For every charge carrier that enters a capacitor, a matching charge carrier leaves it. Ratch
  9. R

    Darlington transistor hfe.

    You might want to read the posting I made on another site concerning pass transistors. It uses a big resistor to take most of the heat instead of dissipating it with the pass transistors. https://www.electro-tech-online.com/threads/bullet-proof.146490/#post-1240701 Ratch
  10. R

    how can i adjust the Av gain of this amplifier from 12 to 10, the AC signal is 10mV, 1kHz,

    Why do you have your base voltage so low (1,.5 volts)? That makes your collector voltage 2.35 volts. You are only 0.85 volts from saturation. Try making the base voltage one-third of the voltage source, so as to be 4 volts. If you have a scope, see that no clipping is present. Ratch
  11. R

    Voltages - continuation of the discussion

    If the battery is already connected when you first become aware of this circuit, then the caps are already fully energized. No current is present, and the charge flow has already taken place. The only thing left to do is calculate the voltages across each cap. Ratch
  12. R

    Voltages - continuation of the discussion

    I am sure there are many such problems that suggest you try to divide something into shares that are not aliquot parts of the whole. The variation I remember is an estate of a rancher whose horse herd was not divisible by integers according to the fractions specified by his will. The slick...
  13. R

    Voltages - continuation of the discussion

    Not the same thing. A cap stores energy, a valve tap does not. Pressure if present before and after the tap is turned on or off. The effect of a cap takes a transient amount of time, a water tap's effect is immediate. A valve is not the same as a storage element. I wish I knew to what you...
  14. R

    Voltages - continuation of the discussion

    Assume three caps designated c1 = 1 farad, c2 = 2 farads, and c5 = 5 farads are connected in series across 8 volts. The caps have no initial voltage. Since Q = C V, and the same imbalance of Q is present in all caps in series, the voltage equation will then be; x/1+x/2+x/5==8 -----> 10x+5x+2x...
  15. R

    Voltages - continuation of the discussion

    My assumptions were that there was no initial voltage on any of the capacitors, and only a DC voltage was applied. I also assumed the circuit did not contain any resistance. If resistance was present, then a full solution would have to show the voltage varying according to time. Resistance or...
  16. R

    Voltages - continuation of the discussion

    It is a DC problem, not an AC problem. The time for final values of voltage will depend on the resistance in the circuit. That is a fact, not a complication. Ratch
  17. R

    Voltages - continuation of the discussion

    Yes, I was thinking of the 12 volt problem Dorke submitted to me. Well, the connection or switch on had to be made at some specific time. Your feet are not in the circuit. Ratch
  18. R

    Voltages - continuation of the discussion

    Agreed. That is what I more or less said. It will also work if only the voltage source has some resistance and the time after activation is long. Ratch
  19. R

    Voltages - continuation of the discussion

    Yes, that will work if there is no real resistance in the problem and the only interest is the voltage after a long time. But if RC is present in the circuit, that method breaks down. Ratch
  20. R

    Voltages - continuation of the discussion

    A step voltage is what a switch does. I don't see any resistance leakages documented in the problem or schematic. Not much ionization at 12 volts. I am just doing what the problem specifies. Ratch
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