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  1. K

    State Variable active filter

    It looks as though it is the front end. Am I right?
  2. K

    State Variable active filter

    There exists more than one design for the opamp. I can't remember which part of the opamp is the high gain. Was it a pushpull at the front end or the middle part?
  3. K

    Basic electronics

    There are two types of comparators. A voltage difference exists and the output goes either high or low depending on the polarity. The second comparator is a digital device. It compares two digital sequences that are weighted and outputs either a greater than, a less than, or an equal to. I think...
  4. K

    Acoustic Generator

    I think a sweep input implies that two signals act on each other. I don't think there has to be modulation. I think the sweep part has to do with the fact that the other signal can have any time base. You can get interesting results when you combine two signals. The TTL output is your normal...
  5. K

    State Variable active filter

    I really like how someone posted the opamp schematic next to the state variable filter. I have been able to draw some conclusions about the opamp circuit in the past. I have guessed that the input transistors are low current. Am I right? So the variable filter really stumps me. I think this one...
  6. K

    Capacitor variety

    I have a homemade inductor that I will use in a power supply circuit. It has a very high current rating, but it does not obey the equation very well. It is made with many strands of magnet wire, combined together, then wrapped around a transformer core. When I increase the frequency 10 fold, it...
  7. K

    OPAMP questions

    Did you know that positive feedback is different than phase shift. The phase shift margin needs to be less than 360 degrees, but positive feedback can occur at any time.
  8. K

    0-30 Vdc Stabilized Power Supply

    This power supply looks a little simple. I would design my own and forget about the opamp, most likely. With so many possibilities, you have to wonder what the ideal operation is. This is the circuit I use presently, but I need a better one.
  9. K

    OPAMP questions

    I have noticed that the BW is very narrow on some opamps. Why is it so narrow? Do you think it is the transistors they use? Maybe the sheer number of transistors and their associated capacitive properties contributes to the overall reduction. So I think this is the frequency at which the...
  10. K

    What is a reasonable frequency?

    The high frequency aspects of the inductances and capacitances are something I don't want to deal with. You must also know the characteristic of your measuring device. This will be a bridge or simple circuit. The final measurement device will be a DC meter or AC meter. Can I safely say that...
  11. K

    What is a reasonable frequency?

    I am looking for a frequency that is not too high. I think the oscillator circuits get too clumsy at higher frequencies. I know that the transistors exhibit strange properties at higher frequencies, but how high. There is bound to be a graph that shows this. Anything that produces variability...
  12. K

    RJ45 network card to IR

    I am refering to the project found on your home page. What is going on with the batteries? Please explain the relative voltages surrounding the photodetector, which is forward biased. Are the two batteries working together? Project link: http://www.electronics-lab.com/projects/pc/023/index.html
  13. K

    OPAMP questions

    How does one go about making sense of an opamp configuration? Start with a zero bias? Would you replace the capacitors with resistors? Do you use the maximum supply voltage? What are some primary concerns when designing an opamp?
  14. K

    handy tip for intefacing your PC with projects

    I just read that the PS2 system is bidirectional and that this is an improvement. When they talk about I/O ports they are not implying bidirectional data. Am I right?
  15. K

    OPAMP questions

    I think you are talking about the amplification and the voltge dividing. Zero current into the opamp and that sort of stuff. I think the gain in a nondifferential situation is high but is limited by the zero current factor. The gain would have to be high because of the small change in base...
  16. K

    handy tip for intefacing your PC with projects

    I am using one of the newest editions of WIndows. I work with XP and Millenium. By in do you mean an in to an out? The printer port can't receive data. Am I right?
  17. K

    motor controller protocols

    Is a stepper motor a digital input device? Is it a DC motor? I have never seen one. Any information about them would be appreciated. I have heard that motors generate a feedback voltage. Does this happen when they change direction? What is the electronics representation of the motor in terms of...
  18. K

    OPAMP questions

    What is the accuracy difference between using the opamp differentialy as opposed to not. It is my understanding that the inputs require changes in current to function best. The example opamp shows no signal applied to the input. I think the changes in current are too small, although the signal...
  19. K

    5 volt regulated power supply HELP!!!!

    A zener diode is being used as the regulator in many of your circuits. If you use the zener diode as a voltage reference only, then it becomes more accurate because of the small change in current. If you use it as a regulator, then it's less accurate. Also, if you use it as a regulator, put it...
  20. K

    OPAMP questions

    You can see from the evidence, a lot of opamp configurations, that the designers are willing to put anything around an opamp. Every single one of those configurations acts differently on the bias. Does anybody else think that the opamp is being too lenient when it comes to external circuitry.
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