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  1. audioguru2

    0-30 Vdc Stabilized Power Supply

    Hi Waldo, Yes, you found the latest revision of the project.
  2. audioguru2

    0-30 Vdc Stabilized Power Supply

    Then you built the original project that has problems with many parts being overloaded and it is not reliable. That is why we fixed and improved it in the forum for the last 6 or 7 years. The tiny little 2N2219 was an old video amplifier transistor that cannot use a good modern heatsink. We...
  3. audioguru2

    heavy duty, realiable dc power supply

    The 30V/3A lab power supply project in our projects section does not work properly and is not reliable because many parts are overloaded. I fixed it and the fixes are in two threads in the forum.
  4. audioguru2

    heavy duty, realiable dc power supply

    With all the series diodes feeding emitter-followers and the fuse then there is no voltage regulation. It has the LED shown backwards which shows how much that site knows about electronic circuits. The rectified and filtered 30VAC produces +40V. If the output is shorted or the voltage is set...
  5. audioguru2

    Inductive sine wave to 5v square wave

    You cannot use a 43 years old design (a 741 opamp). The datasheet for an LM393 dual comparator shows that its inputs can go below 0v if the input current is limited but the output might go high or go low which you do not want. Attenuate the input so it never goes negative more than 0.3V.
  6. audioguru2

    heavy duty, realiable dc power supply

    The circuit you found is poorly designed. Its max output voltage is 20V, not 30V. The 18VAC transformer would produce a rectified and filtered +22VDC to feed the LM338 ICs if the filter capacitor is about 15 times larger. If the output is shorted or is set to 4V with a 20A load then each LM338...
  7. audioguru2

    Inductive sine wave to 5v square wave

    You have the (+) input of the opamp at +4.5V and you have the (-) input at 0V. Its voltage gain is about 200,000 so its output will be saturated as high as it can go. But the minimum supply for a TL082 is 7V and most will not work properly with only 5V. Most opamps are destroyed when the input...
  8. audioguru2

    My Sound Level Indicator project

    I don't believe it. Two series connected LEDs in my project  http://www.electronics-lab.com/projects/motor_light/002/index.html don't work anymore. They are the second-lowest ones so they have been turned on most of the time at about 25mA for nearly 6 years. I thought the LM3915 driver IC had...
  9. audioguru2

    0-30V Stabilized Power Supply

    The latest schematic and parts list is on page 55 of this thread. Then the output transistors must dissipate a maximum of 49W more heat than with a 28V transformer. The driver transistor will also get too hot.
  10. audioguru2

    0-30V Stabilized Power Supply

    The original project has many errors so it does not work properly and it is not reliable. therefore we fixed it in this thread and in another thread in the forum. If the positive unregulated supply from your 24V transformer is 32VDC and the output to the load is 5V then the output transistors...
  11. audioguru2

    Need Solution for this Simple Stupid Question

    The switches simply turn on the fan or turn off the fan. It is not harmful. Why do you have two switches in parallel?
  12. audioguru2

    Need Solution for this Simple Stupid Question

    If your fan is made to use 230VAC then how can it burn? If one switch is turned on or both switches are turned on then the fan turns on. If both switches are turned off then the fan turns off. A "2-way" switch and its wiring are different. each switch in a 2-way switch circuit can turn the fan...
  13. audioguru2

    insulated cables for power signals

    Insulation does not prevent crosstalk. A shield (coaxial cable) reduces crosstalk.
  14. audioguru2

    0-30V Stabilized Power Supply

    The latest schematic and parts list is on page 55 of this thread.
  15. audioguru2

    simple voltage detect - wide range

    An opto-isolator has a range of gain maybe from 2 to 20, not just 10. Its gain is not steady, it changes with temperature and with age. Your circuit uses old relays to switch ranges, my DVM doesn't. Your circuit will instantly burn out its LED when set to a range that is too low, my DVM...
  16. audioguru2

    0-30V Stabilized Power Supply

    The original project has many problems, is not reliable and does not work properly. The revised project works perfectly and is reliable. It has adjustable voltage regulation and adjustable current regulation. It you short the output at any setting then it smiles and simply gets warm.
  17. audioguru2

    0-30V Stabilized Power Supply

    Thank you for telling us the very important details of your transformer. Since it has two 30VAC windings then it can power two of the circuits. You can connect them in series to get up to 60V or have one as a positive supply and the other can be a negative supply. The regulated supplies use...
  18. audioguru2

    0-30V Stabilized Power Supply

    The transformer's voltage is also important. Why do you want 2 psu's? You will not be able to connect then in series and will not be able to connect them in parallel. You will not have a positie psu and a negative psu which is possible with 2 transformers or with 2 windings on 1 very powerful...
  19. audioguru2

    Analog Comparator circuit simulation

    You are posting your project on too many websites. I replied on another website a few minutes ago the 3 reasons why your circuit will not work and which parts will probably blow up.
  20. audioguru2

    Analog Comparator circuit simulation

    You saved and posted the schematic as a very fuzzy JPG file type instead of as a very clear GIF or PNG file type. So we can't read the tiny numbers on it. If the parts are closer together then the schematic and the numbers on it can be bigger. I cropped part of it, zoomed in on it and increased...
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