Search results

Search Forums New Posts
  1. crutschow

    How to remove D-Protection on LG Home theater

    Continually repeating the same request is unlikely to get different results.:rolleyes:
  2. crutschow

    Looking for Replacement 4700 uf 25v Capacitor to Fit My Subwoofer

    I'm sure the capacitors will work fine at an angle. I know ascetically you want it to look like the original, but since it's not normally seen, why worry about how it looks?
  3. crutschow

    Looking for Replacement 4700 uf 25v Capacitor to Fit My Subwoofer

    Smaller caps may have a shorter operating life than the larger ones. If you go with an axial lead device, you might also consider a slightly higher voltage device (e.g. 35V) to help improve reliability.
  4. crutschow

    Looking for Replacement 4700 uf 25v Capacitor to Fit My Subwoofer

    Assuming that height is not a problem, you may be able to fit an axial lead type (below) by standing it vertically. It may require splicing a wire to the top lead to make it long enough to reach the board hole, but wire length is not a factor in the application of this capacitor.
  5. crutschow

    Class D audio amp

    Because of oversampling, I think any of that small PWM phase-shift from sample to sample would not be audible, as it's occurring at ultrasonic frequencies, and would be filtered out by the output PWM filter. But I'm willing to be proved otherwise.
  6. crutschow

    Class D audio amp

    But the shift is constant from pulse to pulse so show me how that creates distortion. :confused:
  7. crutschow

    Class D audio amp

    Sorry but I have no idea what that means in regard to generating a PWM signal. :confused: There is no "sampling" as such.
  8. crutschow

    Class D audio amp

    What "sample and hold" ? You seem to referring to a different thread.
  9. crutschow

    Detect 5v button push on separate system

    An opto isolator, such as a 4N25, may also work for this purpose.
  10. crutschow

    Class D audio amp

    The "skew" is just a shift in time of each PWM pulse from the center of the sawtooth. Since that is a constant shift for each pulse, I don't see how that can add distortion to the modulated signal.
  11. crutschow

    Generator & Battery in Parallel

    Yes, it does rather sound like the common "hey, I just invented a perpetual-motion, over-unity motor-generator device". :rolleyes: Of course you need a battery to get it started.
  12. crutschow

    Class D audio amp

    How does whether its a triangle or a sawtooth affect the duty-cycle accuracy of the square-wave? Either a triangle or a sawtooth will generate a 50% duty-cycle when the modulation input is 1/2 the PP voltage of either wave-shape.
  13. crutschow

    Class D audio amp

    How does that affect linearity? I would think it would be the linearity of the wave slope that determines the linearity.
  14. crutschow

    Unequal heating elements in series - brain fog trying to work it out!

    You could use one of those 240V to 120V traveler adapters to power the two elements in parallel, which would then give a total of 75W + 40W = 115W.
  15. crutschow

    Class D audio amp

    For your interest, here's the LTspice simulation of a PWM circuit using a transistor sawtooth generator with about a 250kHz frequency, along with a fast LT1720 comparator: The Demod output is from a low-pass filter to show the demodulated PWM signal.
  16. crutschow

    Timing circuit using LM339

    The feedback load is R5 (10k) in series with the parallel value of R3 and R4 (also each 10k). Thus the feedback resistance is 10k + 5k or 15kΩ.
  17. crutschow

    How can I change in LTSpice 555timer frequency??

    Yes, you must consider the tolerance of the real components you use. The NE555-1 model I posted should give close to the real timing values if you include the various tolerances in the simulation.
  18. crutschow

    How can I change in LTSpice 555timer frequency??

    Here are the 555 transistor model files. I had to zip them since this website, in their infinite wisdom, won't allow me to download LTspice model files. The .sub file goes in the LTspice lib/sub folder, and the .asy file goes in the lib/sym/misc folder.
  19. crutschow

    How can I change in LTSpice 555timer frequency??

    Do you have any other 555 models in LTspice? If not, you need to download the 555 transistor model, which I can post if you want.
  20. crutschow

    Latching switch to momentary switch

    If the circuit transmits whenever there is power, then we need a circuit diagram to understand how to make it transmit only once.
Top