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  1. audioguru2

    need help for cfl lighting

    I have never seen a transformer with an extra winding like that. It must be custom-made for the light.
  2. audioguru2

    indulis or Audioguru?

    Hi Mik3ca, The question was why didn't he get big inductive voltage spikes. I answered with reasonable answers. We don't know why because we are only guessing why. There are too many unknowns to determine exactly why. We ended up with many "maybes". I have never connected a Mosfet to an...
  3. audioguru2

    Bass guitar effect pedal (need help)

    Of course it will if the little amplifier or the filter are overdriven. If the power amplifier is overdriven instead then it won't make any difference.
  4. audioguru2

    PSU WITH LCD VOLTMETER--TROUBLE!!

    A positive 5V supply and the negative 5V supply made by the IC circuit I showed add to 10V. 10V is more than the 8V minimum.
  5. audioguru2

    Bass guitar effect pedal (need help)

    You will like it both ways. Use a switch to select which way.
  6. audioguru2

    Bass guitar effect pedal (need help)

    Turn up the volume and hold your guitar near the speaker for a loud fuzzy sustain. The LM386 will be feeding 0.5W to heat the 25 ohm reostat and heat itself with 0.29W. The battery current will be 88mA and a little 9V battery won't last long. Do the same with a 1k pot and the battery current...
  7. audioguru2

    Bass guitar effect pedal (need help)

    Hi ReCoC, You have a bass guitar but the amplifier circuit has an input capacitor value so small that it cuts bass frequencies below about 1600Hz and is half power at 320Hz. Increase the value of the capacitor 22 times to get some bass. Also, the gain pot is wrong, it is supposed to have a...
  8. audioguru2

    my radio is changing stations by itself!

    The output of a Cmos logic IC goes to the supply voltage when high, only if it is not supplying current to a load. The outputs are tiny little Mosfets that have an internal resistance when they are turned on. So if the load draws 0.88mA then the output voltage typically drops 0.4V. A weak one...
  9. audioguru2

    Why doesn't my inductor give more kick.

    I think the input cable to his 'scope is arcing at about 100V and is arresting the voltage spike. The input overvoltage protection circuit of the 'scope might be active during the voltage spike. The spike happens so quickly that he blinked each time and missed seeing it. ;D
  10. audioguru2

    need help for cfl lighting

    It is a huge paper with a tiny schematic on it. Make it, measure its current and see how dim or bright it is. Are you going to take it camping? The bears might eat it. ;D
  11. audioguru2

    non stepper motor controlling bridge problem

    Its max current is only 300mA. Is your motor that small?
  12. audioguru2

    0-30 Vdc Stabilized Power Supply

    You are correct. I didn't know the max voltage is different from different manufacturers. It is only 36V max from National Semi and Texas Instruments. 27VAC at full load will rise to about 28.5V without a load. 27VAC makes 41.8VDC adding the positive and negative supplies. 28.5VAC makes 44.5VDC...
  13. audioguru2

    my radio is changing stations by itself!

  14. audioguru2

    non stepper motor controlling bridge problem

    A 1N4004 is a rectifier diode for 50Hz or 60Hz and is very slow. PWM at high frequencies needs faster diodes. I don't have a list of fast diodes. I need one also.
  15. audioguru2

    0-30 Vdc Stabilized Power Supply

  16. audioguru2

    0-30 Vdc Stabilized Power Supply

    Maybe you have a bad opamp. The typical input offset voltage of an OPA445AP opamp is only 1.5mV and only 5mV is its max. The voltage across R17 when P2 is turned all the way down is 5.6mV. Connecting a 1N4148 diode across C8 might fix it, cathode to pin 6 of U3. I still think your negative...
  17. audioguru2

    non stepper motor controlling bridge problem

    Its datasheet shows where to connect external diodes and how it is used with DC motors having brushes and a commutator. If your motor draws more than 1A when starting, working hard or is stalled, then the IC will make lots of smoke.
  18. audioguru2

    my radio is changing stations by itself!

    The voltage from unregulated DC adapters varies all over the place. Then your varactor's tuning varies all over the place. You need a voltage regulator for your project. The CD4040 has a very low amount of output current. If the resistor values in your DAC are too low then the output voltage...
  19. audioguru2

    0-30 Vdc Stabilized Power Supply

    Hi Markus, Welcome to our forum. ;D I think the -5.6V supply in your project is weak. It collapses when the 4mA of current in R20 and in U3 turns on Q3. Check the parts in the negative supply circuit.
  20. audioguru2

    motor driver L298 help

    Hi Rod, Thanks for not running away. ;D Well? What kind of motors are you using? A DC permanent magnet motor with brushes, a commutator and only two wires? Or a DC permanent magnet stepper motor that has 4 wires or more?
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