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  1. HarryA1

    Best Amp for 0Hz-100Hz square & sawtooth signals driving coils for pulsed magnetic fields.

    Q: Can the module amplify square wave or pulse? What is the module bandwidth? A: The module can amplify low-frequency square waves or pulses. Because it is an audio amplifier, the total bandwidth is not high. Signals within 100K can be amplified. The module is compatible with DC input. This is...
  2. HarryA1

    Best Amp for 0Hz-100Hz square & sawtooth signals driving coils for pulsed magnetic fields.

    The OPA548 op amp looks promising. It has up to 5 amperes output into 4 ohms or better. It can be bought in a complete amplifier see OPA348 on Ebay or Amazon.com just search for OPA548. The data sheet is here: https://www.ti.com/lit/ds/symlink/opa548.pdf As the amp can be used in a dc pwoer...
  3. HarryA1

    Best Amp for 0Hz-100Hz square & sawtooth signals driving coils for pulsed magnetic fields.

    See the LM3886T at: https://www.alldatasheet.com/datasheet-pdf/pdf/8893/NSC/LM3886T.html?link=https%3A%2F%2Fwww.alldatasheet.com%2Fdatasheet-pdf%2Fpdf%2F8893%2FNSC%2FLM3886T.html  It has a sample circuit with no capacitors in the pdf file. Also this amp board maybe useful, what ever "Pure DC...
  4. HarryA1

    Integrated circuits connectivity in Printed circuit board.

    I am not to sure what your question is. Are you asking can IC by its self, not in a package, be connected to a circuit on a PCB? Yes but it would need power and ground, etc connections also. An IC in a package like a DIP can. For example in the CDI (capacitor discharge ignition) circuit,that I...
  5. HarryA1

    Room noise cancelling

    Also sounding proofing outside going doors and windows with heavy fabric is said to help. Plus having sound absorbing rugs and wall hangs reduces the unwelcomed sounds. I see one cannot edit previous postings.
  6. HarryA1

    Room noise cancelling

    Some years ago there was research on noise suppression by picking up a noise and playing it back 180 degrees out of phase. If you played a sound through two speakers connected out of phase, that is so when one cone came out while the other went in, would they tend to cancel? Thus creating a...
  7. HarryA1

    0-30 Vdc Stabilized Power Supply

    My guess would be that D!! and C7 are to suppress superfluous  outputs on at the power outputs. D10 is part of the biasing for Q2 transistor? Member audioguru is far more knowledgeable of this circuit than I; hopefully he will come by and give an expert input.
  8. HarryA1

    Light font?

    I see little or no difference using Firefox, Opera, or Edge. I am thinking that it is my monitor. Watching to many "Extra History" videos on YouTube.com is wearing out the pixels 📺 Thanks for trying.
  9. HarryA1

    Light font?

    The font: "The font:" above is much lighter than the uploaded example. I could not see how to continue with the next image so I  am here. I am using an HP x20LED; I can not get to the model number. Lets see what others say. For login one does not see the "Display Name" nor the "password"...
  10. HarryA1

    Light font?

    Is it me or is the forum running out of toner? The font seems to be getting lighter over time. I can not adjust the browser to improve it. Also at login there is no physical response; the login area is down below the screen so one thinks nothing happened. Just trying to be helpful 😀
  11. HarryA1

    TDA 7418

    Although it is for the Arduino there is a library plus others here that maybe helpful for you to look over: https://github.com/deskwizard/TDA7418_arduino scroll down to see the implemented functions.
  12. HarryA1

    PCF8575

    What are you connecting the PCF8575 to?  You most likely need to include some type of library.
  13. HarryA1

    Sleeve Antenna

    You can find some information on the sleeve balum that maybe helpful here: https://en.wikipedia.org/wiki/Dipole_antenna
  14. HarryA1

    ZY12PDN USB C 3S 12V Li Ion Battery Charger

    I would think you need a power supply  that is USB C compatible and supplies 15 volts like this one perhaps...
  15. HarryA1

    Uc3825 based smps issue

    I would disconnect one end of R35  and see if that fixes the problem or just replace it. It maybe breaking down under the higher voltage?
  16. HarryA1

    PANASONIC SERVICE MANUAL SCDM3 NEEDED

    https://www.manualslib.com/manual/119606/Panasonic-Sc-Dm3.html#manual
  17. HarryA1

    Help identifying electronic components

    If you compare your  board with the one on Ebay that one looks like the better board. You may gain some insight by comparing the P6? on your board with the three in the schematic and see if it connects the same as one of them. This is the schematic of the Viber12a in a battery charger.
  18. HarryA1

    Cherokee International SMPS Model# SP671-Y01A

    There are used Cherokee International power supplies  on ebay.com if that is any help.
  19. HarryA1

    Help identifying electronic components

    Yes, you are not the only one with that problem! See the circuit here: https://www.ebay.com/itm/Polk-Audio-DSW-PRO-500-Subwoofer-Amp-Plate-Not-Working-For-Parts-Repair/184441091699?hash=item2af18bb673:g:2~QAAOSwEkxfWY2A I was thinking you could get the correct parts from that one but no such...
  20. HarryA1

    Help identifying electronic components

    The eight leaded DIP is a " Low power offline switched-mode power supply primary switcher" see: file:///C:/Users/harry/AppData/Local/Temp/viper12a-e.pdf The larger diode P6? maybe a protection diode to protect from over-voltage. The  two smaller diodes most likely  are rectifiers used as part...
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