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  1. Alec_t

    help with IR2110 chips

    I've already said I wouldn't buy anything more yet :)
  2. Alec_t

    help with IR2110 chips

    Looks right. I was thinking 14 per cm but omitted the 2cm. My bad. Guestimate re-called from this thread. With 2800 neat turns, average diam 3cm, turn circumf = pi*3 cm, wire length = pi*3*2800 = 264 metres. Doesn't sound right. If 264 metres, with copper density 8.94g/cc, that would weigh...
  3. Alec_t

    help with IR2110 chips

    Depends how the influence of a high permeability small diameter core varies with the radius of a bigger turn. Haven't researched that, but gut feeling tells me the influence drops off rapidly with distance. For my rough guestimate I assumed only 1 layer had u=2000 and 13 layes had u=1. That gave...
  4. Alec_t

    help with IR2110 chips

    Assuming your 5cm diam coil is wound on a 1cm diam core, is 7.5 cm long and wound with 0.7mm diam wire you should get about 100 turns per layer and about 14 layers. Assume core relative permeability is in the 1000-3000 region for layers near the core but about 1 for layers near the outside of...
  5. Alec_t

    help with IR2110 chips

    On second thoughts, for a given wheel rotational frequency the coil output frequency per energisation pulse is dependent on the magnet size relative to the rotational circumference, so impedance should be relatively independent of the number of magnets. Using this calculator, your present coil's...
  6. Alec_t

    help with IR2110 chips

    I don't even know which country you're in. I'm sure Google will know a likely source of wire.
  7. Alec_t

    help with IR2110 chips

    Having more magnets will increase the frequency at which each coil gets energised, so coil impedance due to inductance will increase too. Have you considered the effects of that? From your pics it looks like the coils are quite bulky and unlike the air-cored pancake ones often seen on axial flux...
  8. Alec_t

    Repair to Control Board PCB of Whirlpool Oven

    Good to know it's working.
  9. Alec_t

    help with IR2110 chips

    Experiment time.
  10. Alec_t

    help with IR2110 chips

    2 x pi x 7 / 2.5. I thought you were using a different wheel from the one in the pic.
  11. Alec_t

    help with IR2110 chips

    By my calculations, using the dimensions you provided, the maximum number of magnets you could fit round a 7cm radius circle would be 18, for 100%. So 16 comes close. I guess the need to separate alternating poles or not would depend on the field characteristics of the magnets.
  12. Alec_t

    help with IR2110 chips

    If the magnets were at a greater radius their tangential velocity would be greater and so would the coil voltage, albeit the coil pulse would be narrower. It gives a better estimate of the duty cycle. Looking more like 60% with 10 magnets, compared to 50% with 8.
  13. Alec_t

    help with IR2110 chips

    500 posts already !!
  14. Alec_t

    help with IR2110 chips

    As you will have seen from the waveforms in my posted sims, the sims model each coil being energised by a passing magnet more or less continuously, i.e near 100% "duty cycle". However, that would require no, or very litle, angular spacing between magnets. In your machine, what is the magnet...
  15. Alec_t

    help with IR2110 chips

    Of course I/you can, but that won't give the voltage you want at the current you want.
  16. Alec_t

    help with IR2110 chips

    I can't do it with one coil.
  17. Alec_t

    help with IR2110 chips

    Then your generator will need to give a rectified ~15V DC out at >1.2A.
  18. Alec_t

    help with IR2110 chips

    That would provide the power, but not necessarily the voltage. If you've designed your inverter around a 50Hz 1:8 step-up transformer and want 240V rms out, that implies the inverter needs 30V DC input, so your generator would need a 30V DC output able to provide > 0.6A. I wouldn't get anything...
  19. Alec_t

    help with IR2110 chips

    Just running some numbers: If the max voltage from your 7 Ohm coil is 14V and we assume its waveform is sinusoidal then its RMS voltage is 14 x root 2, = ~10V. The maximum power it can deliver would be to a 7 Ohm load, so the current would be 10V/(7+7) Ohms = 0.714A, the voltage across the load...
  20. Alec_t

    help with IR2110 chips

    Yes, that's what I meant for voltage addition/doubling. But remove R1, since V1 and V2 include series resistance. Your circuit assumes V1 and V2 coil voltages are in phase, whereas my post #448 one has coil pairs with a phase shift.
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