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  1. Alec_t

    Makita diode failure

    Welcome to maker.pro, Soundzrite, but you're a bit late to the party. This thread is nearly 13 years old!
  2. Alec_t

    help with IR2110 chips

    Parallel connection will help in reducing the effects of coil inductance, but I think the high inductance of those massive coils is what will limit the useful output of your machine.
  3. Alec_t

    help with IR2110 chips

    All the coils need to be phased such that their outputs add rather than subtract. I've lost track of what particular series/parallel combination you want.
  4. Alec_t

    Calculating draw current

    .... providing the secondary winding resistance is insignificant. But suppose it were 1 Ohm. At 0.5A it would drop only 0.5V, which might be acceptable; but at 2.9A it would drop 2.9V, i.e.nearly half the voltage you want.
  5. Alec_t

    Bluetooth Audio Module - Distortion and Quality Issues at High Volume

    Perhaps the distortion is mainly due to the speaker itself, particularly if the '3W' is the so-called 'music power' rating?
  6. Alec_t

    Makita DMR110N Repair - Now Turns On - No Sound

    IC1 looks over-cooked.
  7. Alec_t

    I want to know all of the maths concerning this scissor mechanism!

    Force = mass x acceleration.
  8. Alec_t

    I want to know all of the maths concerning this scissor mechanism!

    I think you're confusing yourself and us by using too many decimal places and not enough punctuation in your posts. :)
  9. Alec_t

    I want to know all of the maths concerning this scissor mechanism!

    You have 4:1 gearing, so the torque at gear 4 shaft = 4 x the torque at gear 1 shaft. The tangential force on the 20-tooth gear is the gear 4 shaft torque divided by the radius of the 20-tooth gear.
  10. Alec_t

    Advice please ! Need to buy a present for an electronic hobbyist

    What test equipment does he already have? What is your budget?
  11. Alec_t

    I want to know all of the maths concerning this scissor mechanism!

    Yes.
  12. Alec_t

    I want to know all of the maths concerning this scissor mechanism!

    The radius (the effective lever length) with that arrangement isn't constant, but fortunately as the weight falls its resolved component at right angles to the lever (which is what produces the torque) varies to compensate, so torque is constant.
  13. Alec_t

    I want to know all of the maths concerning this scissor mechanism!

    That should help. Btw, you realise that if lever 2 has a fixed length then the weight will fall in an arc, not vertically? Alternatively if you want the weight to rise and fall vertically (which the maths to date has assumed) then either lever 2 length has to vary or else the flywheel and...
  14. Alec_t

    I want to know all of the maths concerning this scissor mechanism!

    Try OpenOffice Help.
  15. Alec_t

    I want to know all of the maths concerning this scissor mechanism!

    No. Just click on a Value cell (e.g. D14) and its formula shows in the Formula bar above the column headings. If you need to edit a formula directly then you have to remove the cell protection.
  16. Alec_t

    I want to know all of the maths concerning this scissor mechanism!

    Sorry, but I haven't found the time to update your spreadsheet. I think you have all the maths you need now to do that yourself, using my spreadsheet for guidance as to how formulae are used in spreadsheets.. This project is going way beyond considering the maths of the scissor mechanism, as...
  17. Alec_t

    I want to know all of the maths concerning this scissor mechanism!

    .... in which time the cam rotates 1/4 turn and the cam follower is out of contact with the cam..
  18. Alec_t

    I want to know all of the maths concerning this scissor mechanism!

    I understand the drawing, but it seems to me there's a major problem or two with it. As the weight falls the flywheel will be driven clockwise, but as soon as the cam tries to lift the weight back up again the flywheel would have to instantly reverse direction. That ain't gonna happen, given its...
  19. Alec_t

    I want to know all of the maths concerning this scissor mechanism!

    What number post shows the exact mechanism your spreadsheet refers to?
  20. Alec_t

    I want to know all of the maths concerning this scissor mechanism!

    If it helps, I'm attaching a LibreOffice spreadsheet for this. Delete the ".txt" part of the file extension. Should be compatible with OpenOffice. Dependent variables have formulae shown and their cells are protected.
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