Read about electrical engineering | 188 Discussions | Page 1

  1. A

    Do you have some good advice for an electrical engineering student?

    Summary:: hello there, what are some good advices you would have liked to know when you were a student of EE? Thanks in advance!!!
  2. K

    4160V Reduced Voltage Starter Question (run and shorting contactors are closed at the same time)

    Can someone give me some insight into what would happen at the motor terminals and on the line if 2K2 (run Contactor) and 2K3 (auto xfmr wye contactor) were to close simultaneously. There are interlocks to prevent this, but I would like to know out of curiosity. My theory is that you would have...
  3. K

    Voltage measurement on a Current Transformer (CT)

    I don’t know the ratio of the CT. I’m just looking for an explanation on this. I thought in order to measure output voltage you need to pass the current through a resistor and read the voltage drop. A co worker put 400a through the CT and measured 130v. Something just seems off to me. Can you...
  4. K

    Vacuum interrupter contacts and displacement current

    I’m self taught so I have a lot of holes in my understanding. I also have little to no mathematical understanding. Even though ironically, I tend to prefer to picture electricity as numbers rather than “water” in a pipe, etc. I’ve been studying displacement current recently and have a question...
  5. garthenar

    Comp Sci Boolean simplification of a larger term?

    I was asked to use De Morgans law to find the complement of a particular equation, I applied the law correctly and simplified my solution down to A'B'CD'+CA+CB'+D'A+D'B' I ran the problem through a boolean simplifier to check my work...
  6. Boltzman Oscillation

    Engineering How should an H bridge circuit be analyzed?

    If I am given an H bridge circuit such as that below: How would I go on analyzing it? I would personally replace all of the transistors by their circuit models but then what would I do with the motor? Do I replace the motor with it's load resistance or is there more to it? I guess motors are...
  7. Boltzman Oscillation

    Engineering How do I find the electric fields for this capacitor?

    the image is given here along with some numerical information: Now I know that the formula for the electric field in a capacitor is given as: $$E = \frac{V}{d}$$ which I can use to obtain the three following fomulas: $$E_1 = \frac{V_1}{d}$$ $$E_2 = \frac{V_2}{d}$$ $$E_3 =...
  8. Boltzman Oscillation

    Engineering Help finding the damping ratio formula for this circuit

    The circuit to be analyzed is shown below: Since initial conditions are zero (from the instructions) I will use laplace transforms for the cirucit and I will use the MAME method to solve this circuit. The laplace transforms that are required will give me: $$E_g(s) = \frac{10}{s}$$ $$ L_3...
  9. V

    EE or ME -- which do you find more difficult?

    I seem to be in a minority for thinking that mechanical engineering is more difficult than electrical engineering. Difficult for me, I mean. To me, mechanical engineering is more difficult largely because in mechanics your intuition and common sense are often trying to mislead you. With...
  10. D

    How to calculate the reluctance of an electromagnet

    How do you calculate the reluctance of An electromagnet that consist of a nail with bare copper wire wrapped around it? I have tried searching on the internet. Have not found a website that answers my question. Not wikipedia or any other website.
  11. D

    I have tried building a phase shift oscillator, but it won't work

    I built a phase shift oscillator, but it Won't work. I visit the website and copied the schematic I saw...
  12. D

    Unable to get a Wien bridge oscillator to work

    I am unable to get the wien bridge Oscillator I built to work. This same Circuit has worked several times. Sometimes the same circuit works. Sometimes the same circuit does not work. When it works I can get A led to blink and can build a frequency divider. How do I troubleshoot this circuit...
  13. D

    How to make a comparator out of an opamp

    I have an operational amplifier. I am Trying to make a comparator out of It. I built a voltage divider to provide Different voltages. But I either get The same voltage output regardless Of input or the voltage is too high I think. How do you make a comparator out of an operational amplifier?
  14. D

    Trying to get a microphone to produce a signal

    I removed a condenser microphone From a sound meter. I plug it in a breadboard. But the Condenser microphone won't produce a voltage or signal. I tried yelling into the microphone. I tried Connecting a battery to circuit. Nothing I tried worked. Anyway to get microphone to pick up signal?
  15. D

    How proportional action is produced in a pneumatic controller

    Homework Statement (a) With the aid of a sketch explain how proportional action is produced in a pneumatic controller whose output is 0.2 to 1.0 bar. Assume that the controller is direct acting. (b) Show, mathematically, that the output is dependent on the difference between the measured and...
  16. Boltzman Oscillation

    How can I prove this discrete signal is periodic?

    Homework Statement Prove the discreet signal is periodic: Homework Equations for periodic funtions: x[n] = x[n + N] The Attempt at a Solution I made an equality (im going to leave the sigma out for simplicity): 2^(-abs(n-2m)) = 2^(-abs(n+N-2m)) I dont know what I need to do from...
  17. H

    B Electric arc: How to calculate the required voltage for a light bow?

    <Moderator's note: Moved from a homework forum.> Calculate the required voltage to produce a electric arc between 2 iron nails (distance: 3cm). I´ve read in the internet that you need 1 kV per mm. But how can I calculate this value, that I need 1kV per 1mm?
  18. Boltzman Oscillation

    Engineering What is the output voltage of this ideal diode circuit?

    Homework Statement Given the following circuit: what is the positive and negative peak values of Vo? vi has a frequency of 1kHz, peak of 5V, and is a sine wave. Homework Equations x(t) = Vsin(2(pi)*f*t) KCL, KVL, etc. The Attempt at a Solution [/B] I made Vi to be 5sin(2(pi)1000t) during...
  19. Jason-Li

    Thevenin's Theorem, Superposition & Norton's Theorem

    Homework Statement FIGURE 1 shows a 50 Ω load being fed from two voltage sources via their associated reactances. Determine the current i flowing in the load by: (a) applying Thévenin’s theorem (b) applying the superposition theorem (c) by transforming the two voltage sources and their...
  20. Boltzman Oscillation

    Engineering How to analyze a circuit with one node using the node method

    Homework Statement I have the circuit given below with a single node where R3 and ground meet. How can I solve this problem using the inspection method? Is it possible? I can easily solve using another method but I would rather try using the inspection method. Homework Equations Ax = M A is...
  21. stipan_relix

    How to use Thevenin to find R and I?

    Homework Statement In the circuit shown, in the image, the variable resistor R is consuming maximum power. Determine: a) resistance for R b) power for R c) current for R3 and its direction Homework Equations The Attempt at a Solution I tried getting IA(the direction is shown with arrows...
  22. stipan_relix

    How to find power and voltage using the mesh current method?

    Hi. I am practising for my test and since I don't have the correct answers, I don't know if what I'm doing is right. I tried to solve this problem, can you check it and correct if it's wrong? Here's a clearer picture of the circuit. I suspect Uab isn't right, but am not sure. Thanks...
  23. Boltzman Oscillation

    What is the gain error for this opamp driven by a voltage

    Homework Statement The op amp has a near ideal level 1 model with G = 5000V/V, ri = inf, ro = 0 How would I obtain the feedback function? Homework Equations I know I have to find the feedback function which is: f = - (ΔV/Vin) The Attempt at a Solution I will first drive using the...
  24. V

    Design courses for Electrical engineering

    Which Design courses are available in Electrical engineering for getting good job opportunities
  25. Boltzman Oscillation

    How can I analyze this transimpedance amplifier?

    Homework Statement The opAmp network shown in figure 68 is a transimpedance amplifer that employs both negative and positive feedback. Assuming that the op-amp is ideal, calculate the value for the output voltage for Jg is 1mA. The circuit and question are this...
  26. Lapse

    Engineering Question About A Particular Circuit in LTSpice

    I am simply attempting to design a circuit in LTSpice. We just started on dependent sources. I am having trouble designing this guy here: Here's what I've got: What does this error mean? What do I need to change to make this circuit work?
  27. T dawg

    Courses Which course should I take?

    I'm an upper division physics transfer student and currently deciding on whether I should take a course in numerical methods for physical modelling or basic into to analogue circuits course. Here are there descriptions: math 174 - Floating point arithmetic, direct and iterative solution of...
  28. P

    I THz Radiation, Antennas: Need background knowledge

    I want to use small molecular - preferably CNT - "antennas" to produce THz signals to monitor activity in biological systems. After some googling, I've been reading things like "absorption spectra", "energy bands", "spectroscopy", as well as a bunch of antenna-science related jargon... I need...
  29. akaliuseheal

    Reading datasheets to pick a comparator

    Hello, I've got a voltage comparator, well only on schematics, I need to chose one and I need some help interpreting datasheet. The datasheet I was looking at is of a lm393. My input voltage ranges from -7.8V to +7.8V. The datasheet says -0.3 to something. So it's not usable, right? I was also...