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  1. M

    150A 100V do anything controller

    Time... Circuit and board design about a week, waiting for a suitable time to slip the board in a works prototype order (cough cough) two weeks, three months waiting to get time to build it, 2 days construction, code, haven't started yet I guess a week of evenings. I might even publish it...
  2. M

    150A 100V do anything controller

    It is a OARS-XP-0R002 — WELWYN http://uk.farnell.com/1292585/passive-components/product.us0?sku=WELWYN-OARS-XP-0R002
  3. M

    150A 100V do anything controller

    As it has software adjustable current limit none whatsoever.
  4. M

    150A 100V do anything controller

    What about a few (6) of these!
  5. M

    150A 100V do anything controller

    Ah, any available to buy?? To make it worthwhile on a short production run of say 20 they would have to be 250 to 350 UKP each. These would have standard analogue inputs instead of the digital control there is at the moment and have flying leads instead of the milspec connectors (over a...
  6. M

    150A 100V do anything controller

    And its my birthday today... 0x30
  7. M

    150A 100V do anything controller

    Hi folks, Long time no post, been a bit busy, but my long term new super controller is on it's final run. Basic spec... 150A at 100V using pairs of FDP3651U FETs, with my usual shottkey diode across the body diodes to reduce losses. IR21834 FET drivers dsPIC33FJ64MC506 microcontroller doing...
  8. M

    Home Brew Controller, what would it take ?

    I had a look at the IR three phase drivers, the main problem is trying to track them on the PCB, at least one pair (quad) of FETs ends up a long way away. Also, the drive is a bit low for multiple FETs, if you blow it up all three go (I have got home at least twice on two phases before), more...
  9. M

    Home Brew Controller, what would it take ?

    risisson I would turn the opto transistors the other way up, assuming Vcc is a positive voltage. Or look for logic optos, no need for slow pull up(down)s. To protect the brain part of a motor controller you can simply put resistors in series with the inputs to the drivers, I never have and...
  10. M

    Home Brew Controller, what would it take ?

    Have I missed the obvious? won't both output FETs turn on at the same time? And I think your turn off times will be very slow (= hot FETs) you need to pull somewhere near an amp to turn off a big FET quickly enough. Do take a look at the IR drivers it will save a lot of hassle, you have to...
  11. M

    Home Brew Controller, what would it take ?

    Rsisson, Here is the design for my controller, you can 'read' it by downloading Seetrax Ranger 2XL from seetrax.com, you don;t need a licence to view.
  12. M

    Home Brew Controller, what would it take ?

    Fecher, Most of the IR chips come with a bootstrap built in, you just have to make sure the fets switch to 0V on a regular basis to charge it. In my controller the maximum PWM is limited to 1/1024 so there is at least a wee bit of charge every cycle. I have only killed one by putting 40+...
  13. M

    Home Brew Controller, what would it take ?

    Hi folks, yes been a bit busy. Thanks for the complements on the controller, somewhere here there is all the insides too (search under author). Currently working on a) rewinding a 40X motor to give less copper loss ans b) an even more unbreakable controller. The new controller is needed as...
  14. M

    Help Safe Make His Motor Current Limiting Controller

    You could go my totaly OTT route and have 2 DSP chips!
  15. M

    Phase advance to increase motor speed

    The7, I am shure I posted the result, well here it is again, bugger all difference in speed lots more current. Conclusion, I won't bother.
  16. M

    bmc/puma windings

    The step is two windings not quite being trapezoidal and not meeting exactly (electricaly not physicaly). If you take a look at my non skewed simulation you will seee where it comes from.
  17. M

    bmc/puma windings

    The Xlytes (and many more good BLDC motors) are designed with a trapezoidal BEMF to generate that 1/6th of a cycle flat top so they are compatible with a rectangular waveform drive. The flat top gives a constant current drive (Drive volts - BEMF) / motor resistance. Sinusoidal BEMF on the...
  18. M

    bmc/puma windings

    An setting skew to 0 in the simulation program gives...
  19. M

    bmc/puma windings

    It doesn't round off the top merrily slopes the sides. I will get a real 'scope trace soon.
  20. M

    bmc/puma windings

    Skewed poles tend to make the slopes straight, improving the trapezoidlness(?)
  21. M

    bmc/puma windings

    Still in the process of revamping my workshop (new mill arrived last week) so I put the 409 into BLDC (a motor design program) and got these curves. The smaller one is betwen the centre point and a phase, the larger one betwen phases, memory seems to confirm this is about the right shape for an...
  22. M

    bmc/puma windings

    A BLDC is (usually) wound to give a trapezoidal BEMF, this is done so it can accept a rectangular voltage waveform efficiently. The AC syncronous motor however is wound for sinusoidal voltages. The two tend to get a bit mixed in the real world. The Crystalyte 400 series has a remarkably...
  23. M

    bmc/puma windings

    "But the BLDC have a taperzoidal wave form drive." The back EMF is trapezoidal, the drive is square (well rectangular to be precise). And I did say "the windings anyway", I do read the posts.
  24. M

    bmc/puma windings

    Star (Y) and delta are used quite a lot for starting big induction motors (start in Y run in delta) this is all fine for sinusoidal voltages. Our BLDCs have a square wave drive, whilst this works on a delta connected motor you do get so called 'circulating currents', this wastes some power. Y...
  25. M

    Crystalyte Phoenix motor problem

    Ah... you have the sensor, a bit of heat will degrade the epoxy making it easy to remove, heat it with a soldering iron ans pull.
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