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  1. audioguru2

    Magnetic Induction charged Torch

    I tried one in the store. I shook it until my arm fell off then it lighted dimly for a few seconds. I didn't see any battery inside, but if it had one then it must have been dead like my arm. The new ones have a crank-driven generator. I didn't try it. ;D
  2. audioguru2

    Low-pass Filter?

    A Butterworth filter has a Q of 0.7 to provide its flat response, then its sharp drop at cutoff. If you connect two RC networks in series (buffered, so they don't interact), then they are a Bessel filter, the Q is only 0.5 and the response is sloppy and droopy. ;D
  3. audioguru2

    0-30 Vdc Stabilized Power Supply

    Hi Smit, Your problem is caused by your super-high-speed opamps. They are de-compensated for high speed, so can't be used in circuits with a closed-loop gain less than 5 so that they don't oscillate at a very high frequency. They oscillate in this project: 1) U1 has a gain of 2. 2) U2 has a...
  4. audioguru2

    100W Audio Amplfier By Smart Kit

    No, don't add 1 ohm resistors. The confusing parts list says to use a 0.47 ohm/5W resistor for R2 and another 0.47 ohm/5W resistor for R16. Four 1 ohm resistors are used by people who can't find 0.47 ohm resistors. Your amp's very high current is caused by a shorted P1 or Q7.
  5. audioguru2

    12v amplifier?

    4 ohm speakers will take nearly twice the power of 8 ohm speakers and will be louder.
  6. audioguru2

    100W Audio Amplfier By Smart Kit

    I think the parts list of this project is a mess. Read the note at its bottom: "For R2 and R16 if you don't find a 0,47Ohm place two of 1 Ohm parallel". So the parts list is wrong with 1 ohm/2W for R16. Use 0.47 ohms/5W for R2 and R16 or two 1 ohm/2W in parallel for both to make your own 0.5...
  7. audioguru2

    TDA7052 VS LM386 Question

    Nice comparison. But you didn't blow it up like they do on Mythbusters. ;D
  8. audioguru2

    Home-made bench power supply voltage drift problem question.

    Hi Rdl, The voltage of an LM350 decreases slightly as it warms up. You have a wire-wound pot and its metal increases its resistance as it warms, doesn't it? Maybe your circuit has a high current through the pot. Maybe its other resistor drifts its value. Maybe you used high resistor values that...
  9. audioguru2

    Glaringly obvious errors

    The gate of a power Mosfet has a faily high capacitance. One of your transistors pulls a gate high to turn on the Mosfet then the gate stays charged when the driver transistor turns off, then the Mosfet stays on. Power Mosfets usually use complimentary emitter-follower transistors to charge and...
  10. audioguru2

    Low-pass Filter?

    This is a simple square-wave inverter. Its output transistors switch fully-on then fully-off to reduce their heating. A sine-wave inverter is completely different and much more complicated. If you use a linear amplifier to drive the transformer then the transistors would heat nearly as much as...
  11. audioguru2

    Tssop package -> DIP

    How about the tiny ones with little pimples called "bumps" on their bottom? How in the world would you solder them?
  12. audioguru2

    LM317 works Bad "SOS"

    A constant current source is supposed to have a high output impedance . Yours has a honking huge output capacitor so has a low output impedance. Nothing bad happens if the output is shorted and it is unlikely that the input will get shorted.
  13. audioguru2

    0-30 Vdc Stabilized Power Supply

    That's why the mod'd project uses 2W. -5.6V is normal. At 28VAC with no load on the project, the peak voltage of your transformer is 39.6V, which is reduced to 38.2V by the rectifier bridge. When you add the -5.6V negative supply, some of the opamps get a total supply voltage of 43.8V. I don't...
  14. audioguru2

    Tssop package -> DIP

    I like the name for this tiny surface-mount package "ITTYBITTY". ;D
  15. audioguru2

    100W Audio Amplfier By Smart Kit

    Hi Faizan, Here is how to measure the current. I didn't make this amp, I have lotsa amps. ;D
  16. audioguru2

    12v amplifier?

    I call the missleading ratings for amps and speakers "Whats" instead of Watts. Years ago, the Sears catalog had an asterisk  beside all their Stereo Consoles. The description read: "Our 240W stereo consoles actually produce 4W per channel into 8 ohm speakers from 20 cycles to 20k cycles per...
  17. audioguru2

    automatic audio gain control sites???

    Hi Nolram, A site has many audio articles and projects. It has a discussion of audio dynamic range and how to properly reduce it if required and problems caused by improper automatic audio gain control. It has a good quality audio compressor/limiter project with examples of improper circuits. ;D...
  18. audioguru2

    Simulation Models Creation...

    Some sim software has additional models available as updates. Texas Instruments' TINA sim software has many updates. Maybe models from one sim software can be used on other sim software. They are all using Spice, aren't they?
  19. audioguru2

    100W Audio Amplfier By Smart Kit

  20. audioguru2

    Glaringly obvious errors

    The circuit doesn't have anything to turn off the Mosfets. The transistors are wired strangely.
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