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  1. Arouse1973

    Voltage from rotation

    Yes but very expensive software. It's probably quicker to use the formula I have given you and adjust your design accordingly. Adam
  2. Arouse1973

    Stage Line 500W amp repair project

    Yes that would be another reason Bob, good idea. Adam
  3. Arouse1973

    Voltage from rotation

    Hi The 80% I used was an example to show you how the flux works. It would be quite involved to work it out in reality. It means you only loose 20% of the flux each time which limits the amount of voltage. Adam
  4. Arouse1973

    D.I.Y Speakers-Tweeter Problem :-(

    Beat me by a whisker Bob :)
  5. Arouse1973

    D.I.Y Speakers-Tweeter Problem :-(

    Hello The value looks rather large for a tweeter capacitor. I would expect around 22uF not 3300uF. Formula for frequency roll off = 1/2*pi*R*C = 1/2*pi*8*22uF = 904 Hz The 3330uF cap will have frequency roll off of 1/2*pi*8*3300uF = 6Hz so this is why your tweeter is responding to pretty much...
  6. Arouse1973

    Power banks in parallel to increase A / mAh

    What type of battery is it you are trying to join together? If they are primary cells like lithium Thionyl chloride then yes you will need diode if connecting more than two cells in parallel. The diodes need to have a very low reverse leakage current which conforms to UL regulations. If they are...
  7. Arouse1973

    Help identifying capacitors

    The top figure is the batch number, not important here. The second figure is the value in uF (micro Farad), the bottom figure is the voltage rating. The type is probably general purpose so no special type needed. Watch out for the sizes, some of them will have the same value and voltage rating...
  8. Arouse1973

    Voltage from rotation

    Ok here is a rough stab at it. The reason it's rough is we don't know the actual magnetic flux of the magnet at that distance, I took the Gauss figure from first for magnets. I also made up the coil size and turns, maybe @wdariusw can tell me the size and number of turns. Looking at this again I...
  9. Arouse1973

    Stage Line 500W amp repair project

    Hi Pete Do this again and set the meter to 20 mA range. Is it still 0 mA? Adam
  10. Arouse1973

    Stage Line 500W amp repair project

    Thanks for helping Bob. Adam
  11. Arouse1973

    Voltage from rotation

    Let me see if I can work something out. Adam
  12. Arouse1973

    Voltage from rotation

    I dont see how thinner wire can help only the fact you can wind more on the bobbin but this reduces the Q. You need to do the math and see what magnets and coils you need. Trial annd error will take a while. Adam
  13. Arouse1973

    Creating a Velocity Measurement Tool

    Look at altimeter modules. They are used in lifts and can determine the distance between floors of a building. I saw one sense a few cm of movment of a desk. You might be able interface with one of these. Adam
  14. Arouse1973

    Stage Line 500W amp repair project

    Yes Pete.
  15. Arouse1973

    Voltage from rotation

    You need to remember that small magnetics will never produce that much power transfer. Work it out its easy. You need to remember you are on the outside of the coil. Adam
  16. Arouse1973

    Need help identifying part, possibly a resonator

    Yes look like 2 MHz and 4MHz resonators. The ones with 3 pins don't need external capacitors. Adam
  17. Arouse1973

    Where to find an LED counter?

    I could lend my stores lady, she can count LEDs :)
  18. Arouse1973

    Stage Line 500W amp repair project

    If R108 is going low resistance then you should see over. 3.00 mA. This is where the fun begins, if it's ok you could see something like 2.95 mA. A small difference but it makes all the difference. Adam
  19. Arouse1973

    Stage Line 500W amp repair project

    Ok so it's possible R108 is faulty then, and it's resistance is changing when power is applied. I have not seen this before but who knows. So the only way to do this is to lift the bottom leg of R108 out of the PCB and put a current meter in series with the open connection. Are you happy to do...
  20. Arouse1973

    Electromagnetism

    Yes I agree with that. Maybe include the wording an amount of something that passes a certain point in a specific time period. Adam
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