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  1. HarryA1

    Capacitor Charging with HV Pulses

    I think you would find this free Power Electronics course from MIT very helpful. The math is not to bad 😉 I find it very interesting. There are 38 lectures in all; by the end you have a good understanding of power circuits. Power Electronics
  2. HarryA1

    Problem with my power amplifier Oberton B1200

    I once had an amplifier that played music with no inputs. It turned out that it was a local am radio station; the results of poor grounding. If you have a wee soldering iron try resoldering the ground on the TL082 op amp. Perhaps that will help.
  3. HarryA1

    Capacitor Charging with HV Pulses

    The results from the LTspice simulation. Beware that sometimes the simulators lie. In the first plots the the red line is the voltage across capacitor c1. The green line is the voltage at the mosfet drain. The voltages peaks at 1.34 kv in 24 seconds. The green plot is solid as it is maded up...
  4. HarryA1

    Capacitor Charging with HV Pulses

    I put that circuit into the LTspice circuit simulator but the simulator is not happy with it. I will try later to get it to work. The simulator would give insight into what the currents look like.
  5. HarryA1

    Problem with my power amplifier Oberton B1200

    "After swapping the terminals to the preamp, the hum moved to the other channel." Would not this suggest the problem is in the preamp?
  6. HarryA1

    Seeking Recommendations for Beginner-Friendly Microcontrollers - Emmanuel Katto Uganda

    Yes, I have had problems uploading with long cables. Never with the short blue cables. I see on Arduino forums others have problems unloading with longer cables also. One has to be aware some "USB" cables are for charging only; they lack the center two data contacts. You can look into the larger...
  7. HarryA1

    Seeking Recommendations for Beginner-Friendly Microcontrollers - Emmanuel Katto Uganda

    I use the Arduino UNO everyday. It is well supported on the internet at various forums. It is somewhat dated but a good  beginners microcomputer. You can download the Arduino IDE 2.0 (integrated development environment ) from arduino.cc  The Arduino Cookbook in pdf format is available for...
  8. HarryA1

    Positive flank triggered retriggerable timer?

    By positive flank you mean on the rising edge of the pulse or the pulse top? What is the nature of the pulse train? Voltage and pulse rates. "Need a circuit that can trigger a relay when movement or stop is detected on a axle." How does that relate to the pulse from the timer being on only 0.5...
  9. HarryA1

    A dimmer does the job but is not periodical without the human hand turning up and down the knob constantly.

    Will the first  circuit here do what you want to do? Fading LED circuit. I tried it in the simulator but I have not got it to work yet;  poor connection 🤨
  10. HarryA1

    A dimmer does the job but is not periodical without the human hand turning up and down the knob constantly.

    You say: " one wanted the current to rise lowly from 5 volts to 10 volts each ten seconds,"  Is 5 volts off for the lamp? Also you all say:  "had its light intensity decreasing to zero volts:" That statement is confusing; which is going to zero the light intensity or the applied voltage?
  11. HarryA1

    MOSFET Power module and gate drive connections guidance

    You can get technical support here: https://www.monolithicpower.com/en/products/ev1909-tl-00a.html
  12. HarryA1

    Automatic electric bell using wifi

    If you search on the internet  for "Automatic electric bell using wifi  "you will find numerous articles on the subject:  like: https://www.youtube.com/watch?v=jkG9sUWc1CA
  13. HarryA1

    seven segment display 0,28 inch with 6 pins only / programming etc.

    https://search.yahoo.com/search?p=2381BG-2-6&fr=opensearch
  14. HarryA1

    Dfplayer with Arduino pushbutton and led fading

    What does not work? The LED fade or the mp3  player? What do you wish the push button to do? A: Push the button once and the LED fades on and off until you push it again. B: The LED fades on and off while you hold the button down. Releasing it the fading LED stops.
  15. HarryA1

    Dfplayer with Arduino pushbutton and led fading

    I am not sure what you need but here is code that fades a LED up and down. It does not block your code by using Delay(), You can paste it into your Loop{} or call it as a function. You may wish to play with the int period value and the +/-5 value. Do note which i/o pins you can use with this PWM...
  16. HarryA1

    How to build a millivolt signal conditioning circuit with compensation?

    You could use a microprocessor that has a a/d (analog to digital) converter. Use an op amp (operational amplifier) to increase 20mV signal for the a/d converter get reasonable results.
  17. HarryA1

    Guitar feedback issue at high frequencies - please help

    I prototyped  a couple of passive notch filter circuits including the one Tony posted. But neither were very good; two broad. If I can find an inductor between 150 to 200 mh I will try a parallel resonant band stop filter. This site maybe helpful:  8 Ways Of Resolving The Electric Guitar...
  18. HarryA1

    Guitar feedback issue at high frequencies - please help

    What you need is a notch filter to remove only a narrow band of unwanted  frequencies . There are pedal notch filters on the market but they are pricey. Search on "guitar notch filter pedal". Also see::  https://lambdageeks.com/notch-filter/#:~:text=A notch filter%2C also known as a...
  19. HarryA1

    AC synchronous motor capacitor

    It looks good to me.  I would go with it. Are you building something interesting?
  20. HarryA1

    What are types of Power Management Integrated Circuits, the PMIC

    See: Introduction to PMIC - Part 1
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