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    • CommentAuthorsonoboy
    • CommentTimeJan 21st 2010
     
    Hi Al,. these are set as described. When at rotor lock the triggering is also performed by the micro and with a set frequency. The micro controls everything in terms of pulse width and active clamp time. In this case 280 microseconds active duty and 2.78 milliseconds clamp time. When triggered by the rotor the frequency is the only thing that varies, everything else is constant. Power is measured the same way in both cases.
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      CommentAuthoralsetalokin
    • CommentTimeJan 21st 2010 edited
     
    Well, there you go then. If the pulse width is always 280 us and the frequency slows down, the average power will decrease, of course.
  1.  
    sonoboy
    that seems exactly wht one wuold expct

    sinc you hav sam pulse width then decreasng freqncy decreeases duty cycle and since each puls dissipates approx the same energy then the overall avrage power decreases
    at the extrem if the rotor stops the power will b zero
  2.  
    oh i see its alrdy beeen said
    • CommentAuthorsonoboy
    • CommentTimeJan 21st 2010 edited
     
    This weekend I hope to have some parts in that will allow me to switch the circulating current left inside the toroid after the active clamp back to the supply. This motor was designed to use as little power as possible and that means taking advantage of certain inductive effects, one being the time constant of induction. The only time the current is anywhere even close to flat is when the current is recirculating in the toroid under control of the active clamp. If I can get the RPM's up high enough I expect to recover and re-use most of the energy in the coil. Cannot be done with a conventional pulse motor to the degree that it can here.
  3.  
    Posted By: sonoboyThis weekend I hope to have some parts in that will allow me to switch the circulating current left inside the toroid after the active clamp back to the supply. This motor was designed to use as little power as possible and that means taking advantage of certain inductive effects, one being the time constant of induction. The only time the current is anywhere even close to flat is when the current is recirculating in the toroid. If I can get the RPM's up high enough I expect to recover and re-use most of the energy in the coil. Cannot be done with a conventional pulse motor in ther way I'm thinking.


    So current is rising instead of flat??
    Of course voltage should, stay straight.
    • CommentAuthorsonoboy
    • CommentTimeJan 21st 2010
     
    The idea is to active pulse, immediate hard clamp (active), hold the active clamp long enough to shield, then return what's left over to the source. The lower the resistance of the recirculating path, the less loss.
    • CommentAuthorsonoboy
    • CommentTimeJan 21st 2010
     
    I operate this motor on it's inductive curve so, yes, current is still rising when cutoff.
  4.  
    I hope you are data collecting. An interesting idea. keep us informed.
  5.  
    Posted By: sonoboyMy Sonorbo is consistently dissipating LESS electrical power with the rotor up at speed than it does with an identical drive signal and the rotor at standstill (TDC). For instance, I am using a uniform duty cycle of 280 microseconds and a uniform active clamp time of 2.78 milliseconds. This is the same regardless of whether or not the rotor magnets are triggering this signal or the microcontroller is. Absolutely the same active signal. With a 125 HZ signal and the rotor at standstill, the Sonorbo's electrical circuit dissipates 463 milliwatts. With the rotor triggering the same signal, the electrical circuit dissipates 432 milliwatts at 130 hz. So, this thing uses less power when encountering windage and bearing losses while also cycling at a higher speed.


    How much does it dissipate when the rotor is completely removed, no rotor magnet influence whatsoever, not even static?
  6.  
    Posted By: overconfident
    Posted By: sonoboyMy Sonorbo is consistently dissipating LESS electrical power with the rotor up at speed than it does with an identical drive signal and the rotor at standstill (TDC). For instance, I am using a uniform duty cycle of 280 microseconds and a uniform active clamp time of 2.78 milliseconds. This is the same regardless of whether or not the rotor magnets are triggering this signal or the microcontroller is. Absolutely the same active signal. With a 125 HZ signal and the rotor at standstill, the Sonorbo's electrical circuit dissipates 463 milliwatts. With the rotor triggering the same signal, the electrical circuit dissipates 432 milliwatts at 130 hz. So, this thing uses less power when encountering windage and bearing losses while also cycling at a higher speed.


    How much does it dissipate when the rotor is completely removed, no rotor magnet influence whatsoever, not even static?


    OH...when I first read this I thought that the frequency was varying and you were seeing the effect that I and disco described above. But now that I am rereading it it seems that you are talking about the same frequency pulses, so the pulse shape should be the same, except for the slight decrease in amplitude with the rotor in place.
    So in this case I would have to attribute the difference to that other "orbo effect" : the change in permeability of the cores with and without magnets in proximity. That is, the "Max effect". So with the magnets there, inductance is decreased so pulses at the same frequency take less energy, since you are clamping at a specified time not a specified voltage.

    One thing: you say "using a uniform duty cycle of 280 microseconds" when you actually are referring, I believe, to dwell time (coil on time). Duty cycle is the percentage (or proportion) that the coil is ON of the TOTAL cycle , so simply giving a time value is only specifying dwell, not a proportion of the whole cycle. Duty cycle is from 0 to 100 percent, or from 0.0 to 1.0 of the total pulse. At 130 Hz your full cycle time is 7692 us, so if your are ON for 280 us and clamping for 2780 us, your On duty cycle is about 3 and a half percent. Which is short indeed, but clearly all that is needed.
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      CommentAuthorjohnq
    • CommentTimeFeb 13th 2017 edited
     
  7.  
    Ok, I give up. What?
    •  
      CommentAuthorThicket
    • CommentTimeFeb 13th 2017 edited
     
    Heh. This is what happens when an electrician and a plumber don't like each other.
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      CommentAuthorAngus
    • CommentTimeFeb 13th 2017
     
    You're supposed to run the wire ++along++ the conduit.
  8.  
    LOL johnq
    A little sealant around that wire and you're sound as a pound!!
    • CommentAuthorAsterix
    • CommentTimeFeb 13th 2017
     
    Perhaps a pipe for a built-in vacuum system?
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      CommentAuthorjohnq
    • CommentTimeFeb 13th 2017
     
    Best case is it is a ventilation pipe to the roof. Yes, don't assume your electrician and plumber are mates.
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      CommentAuthorSwissie
    • CommentTimeFeb 13th 2017 edited
     
    Worst case: It's the pneumatic post.

    "Jerry from HR called. He's still missing those paychecks we sent him via the letter shoot."
    • CommentAuthorAsterix
    • CommentTimeFeb 14th 2017
     
    The sad thing is that the electrician probably didn't even realize that he'd created a masterpiece.