2012/1/11 andy pugh <bodge...@gmail.com>: > On 11 January 2012 11:58, Viesturs Lācis <viesturs.la...@gmail.com> wrote: > >> http://docs-europe.electrocomponents.com/webdocs/0dca/0900766b80dca34c.pdf > >> On page nr 9 I found a scheme of "Typical application connection". >> Do I understand correctly that anything within the blue frame already >> is on that board? > > Yes. I would suggest opto-isolators between the IRAMS and the 5i23 or > whatever, though. > >> Anyone willing to consult me? > > I made mine do this: > https://picasaweb.google.com/108164504656404380542/Gibbs#5469721364857131746 > So might not be the ideal consultant > > Mk2 had heatsinking, but I think that died too: > https://picasaweb.google.com/108164504656404380542/Gibbs#5471910659108799346 > I can't recally if it was just the surge-limiter that went, or if it > died completely when I was trying to use it as a VFD with an ordinary > induction motor.
Ok, I think that I finally got it - the heatsink is under the board and only its very black side can be seen... At least I think so after taking a look at next picture, which shows the board from bottom (and without heatsink I suppose). How big was that motor? Should something be differently with AC servo motor? I am not sure anymore that I do understand, what is inside AC servo motor. Normal DC brushless motors have permanent magnets, but I have difficulties understanding, how AC servo drives work (the fact that it still supplies DC to motors is confusing me), so I am not sure anymore that AC servo motors are synchronous electrical motors with permanent magnets. What is the rated voltage of Your rectifier bridge? Yesterday I had a discussion with an electronics guy and he told me, that rectifier bridge should not get warm at all - if that is happening, there is something wrong - either connections, either rated voltage too low and it basically should already be damaged... BTW did You have something for the current sensing and over-current sense? I suspect I would not need current feedback to EMC, because it will have resolver/ encoder data, but I suppose over-current signal could be used as a "fault" signal. I also wanted to ask about GND in the schematics in page 9 of the datasheet: http://docs-europe.electrocomponents.com/webdocs/0dca/0900766b80dca34c.pdf If I understand correctly, then V+ is the place to connect + from power supply, but I do not see GND connected to that chip anywhere. Ok, maybe it does not need GND for motor power, but I suspect there should be something, to which the incoming PWM signals are referenced to. Andy, I also would like to ask, if You could share the scheme layout and list of components that You used with that IRAMS chip, it really seems that I might try to build something. 2012/1/11 andy pugh <bodge...@gmail.com>: > On 11 January 2012 14:11, Viesturs Lācis <viesturs.la...@gmail.com> wrote: > >> >> BTW I was warned that there should be considered protection for the >> board from overvoltages, coming from motors. Is that correct and how >> is that usually implemented? > > Freewheeling diodes. You can see one across every power stage in the > H-bridge. Effectively there is a 3-phase bridge-rectifier built into > the H-bridge, and any voltages > bus voltage are shuttled into the bus > caps. Those need to be big enough to absorb the current without > pushing the voltage too high. > Thanks for the explanation, but I do not get, where to look for them? :) Do You mean the schematics in the manual? Viesturs ------------------------------------------------------------------------------ RSA(R) Conference 2012 Mar 27 - Feb 2 Save $400 by Jan. 27 Register now! http://p.sf.net/sfu/rsa-sfdev2dev2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
