Search results

Search Forums New Posts
  1. L

    Parallel LRC circuit analysis help

    My calculation gives the same total current as above.
  2. L

    Op-Amp input signal question? idk

    Aside from the fact that an 'ideal' op-amp does not have any limitations such as power supply voltage, for this op-amp you are expected to assume the output will provide rail-to-rail ±12V maximum while the input is amplified by a factor of ±100 (polarity of your choice). Now for the big...
  3. L

    mV voltage reference for a comparator

    While I won't claim to have much actual experience using comparators, I thought that they were supposed to have digital outputs or at least an open collector from which you could design an output stage that had good logic levels. Also with their high gain and high switching speed the output is...
  4. L

    mV voltage reference for a comparator

    I really don't understand how a Schmitt trigger will be useful here. The Schmitt triggers that I'm familiar with operate as a comparator with positive feedback at logic-level low-frequency signal voltage and where the comparator reference voltage is not tightly specified. It would seem more...
  5. L

    Tesla coil-Will this circuit work?

    How much current are you planning to push through that LED? What provisions have you made for tuning the final high-voltage transformer for coupled resonance? Although you have shown a core for the final transformer, can we assume that it will be an air core?
  6. L

    mV voltage reference for a comparator

    A peripheral consideration is the source impedance of the sensor signal along with the distance the 30mV pulse must travel to reach the comparator circuit. A wideband amplifier will lower the the signal impedance going into the comparator if it is too high. If the pulse travels more than a...
  7. L

    Someone can help me about some concept in wireless sensor network

    This does not appear to be a book but an article published in the IEEE Computer Society Transactions. Unless one is subscribed to the Transactions, the article can be purchased for $19. >>ABSTRACT<< IEEE Transactions on COMPUTERS Toward Efficient Task Management in Wireless Sensor Networks...
  8. L

    Circuitry homework help please

    Since the switch/lamp-voltage table looks a lot like a truth table, what design hints could a Karnaugh mapping provide? The first thing that stands out is that L1 and L5 are identical. This can only happen if they are in series or in parallel. But parallel won't drop enough voltage so they...
  9. L

    Circuitry homework help please

    Assumption of equality will certainly lead one to the same circuit configurations (because what else is there?), but it irks me that calculated values are so far from the given values yet still deemed close enough, 'approximate'. Makes me wonder whether the given voltages were calculated, or...
  10. L

    Circuitry homework help please

    What does it mean that all voltages shown are approximate? How accurate is approximate? For instance, take the 'all switches closed' configuration. It would seem that there would be two lamps in series with two lamps in parallel. But that would mean that the two lamps in series would each...
  11. L

    Poles and Zero's

    Regrettably, the waiting will continue. My preference is to study topics that may prove useful, while pole-zero diagrams seem to mainly be of academic interest, i.e., useful to answer homework problems but little else. Pole-zero diagrams may have once been more useful in the old times to...
  12. L

    Transfer function for RC circuit

    Looks pretty good to me. I've never used the quadripole method but it seems to work for you.
  13. L

    Transfer function for RC circuit

    Can you show how the transfer function was derived? Did you start with the node equations? What were they?
  14. L

    Transfer function for RC circuit

    Just by looking at the circuit you should be able to determine that the magnitude plot is wrong. There should be two corner frequencies, separated by three decades of frequency on a log scale. The first corner @ -3dB will have a frequency of 1/(R2C2). From there the plot will slope down to...
  15. L

    Transfer function for RC circuit

    Suppose the capacitors were shorted out of the circuit. Then your formula would be Z=(1/R2 + 1/R1). What does that give you?
  16. L

    RC Band-Stop Filter Circuit Voltage out calculation

    There are websites that provide analysis services, such as http://sim.okawa-denshi.jp/en/TwinTCRtool.php but this problem includes a load resistor which complicates the calculation. I don't believe this is a voltage divider problem as it seems to need a full nodal analysis. Have included an...
  17. L

    RC Band-Stop Filter Circuit Voltage out calculation

    What you have there is an RC Twin-T Notch Filter, as shown in the attached image. In theory, at the notch frequency the level of attenuation provided by the twin-T notch filter is infinite. It operates by phase shifting the signals in the different legs and adding them at the output. At the...
  18. L

    flyback transformer question

    It is true that a flyback transformer is not used like a normal transformer, since it is normally driven by the horizontal oscillator on an old-style television (Do they even make those anymore?) Nevertheless, it does generate high voltage in the same manner as an ignition coil. But there are...
  19. L

    design a method to measure the input impedance of digital multimeter

    Indeed it does involve the use of Ohm's law. In this case, Ohm's law as applied to a voltage divider. You will need a stable voltage source to measure, and an appropriately sized resistor. Use the multimeter to measure the voltage of the source, then insert a series resistor and determine how...
  20. L

    Pulse width modulator questions

    It would seem that a counter used with a coil winder would have the purpose to indicate the number of turns of wire that had been wound on the coil. The link between the motor PWM and the turns on the coil would seem to be tenuous at best.
Top