Lolailando, here it is : http://www.irf.com/technical-info/re...g-irmck201.pdf
TR2000
TR 2000,
I don't find the design guide that you mentioned: dg-irmck201.pdf
could you post a link or email it to me?
If there's someone who has the knowledge to try this IC, send me a private email I will provide one irmck201 free to one person.
thanks
Lolailando, here it is : http://www.irf.com/technical-info/re...g-irmck201.pdf
TR2000
I threw together some notes about a possible IRMCK201 based servodrive, mainly copy-paste from datasheets found on the net. see attached pdf.
If we find enough people with experience to do the schematics and pcb design so that the prototype is likely to be successfull then I'm all for it.
For my own needs I'm thinking I want the drive to run in current (torque) control mode and accept standard +/-10 V analog command signal.
Will probably use 20 A powerstage for 1 kW servos and 10 A stage for 400 W servos.
comments anyone ?
anyone with a power electronics background willing to help with the schematics/pcb design ?
Here I tried to understand the pinout of the IRMCK201 by reading the datasheet.
Seems I got most of the pins assigned to sensible functions, but there are two missing, 36 and 59... (I emailed irf about it already )
anyone got any ideas ?
Does anyone know how to get an Eagle library that contains IRMCK201 and other IRF parts? to start designing a board?
thanks
I started a little bit on the schematics.
I use pads since that is what I have at work. The free version of eagle is probably insufficient for this anyway.
lot's of open questions:
- at24 eeprom: what to do with the pins that are not connected
- optoisolation: need to find optoiso that accepts 3.3V input
- need to separate power and logic ground carefully
- emi suppression caps for DC bus
- do we put one braking resistor + IGBT per drive or just one braking resistor/IGBT in the psu and have the drive signalling the psu ?
- what are the op-amps that IR suggests: TLV2374 ?
- use mainly SMD or thru-hole ?
- how many layers for the PCB ?
- EMI suppression caps for DC-bus
- where to put the current sense resistors (irmck201 datasheet has them low-side, ir2175 datasheet has them high-side)
etc. etc.
- connectors: logic DC in, encoder, hall, analog in, HV DC, motor, analog out
If anyone interested could take a look and suggest improvements/additions that would be great !
EDIT: attachments removed, see end of this thread for current version
Last edited by andy55; 12-02-2005 at 03:35 PM.
are Texas Instruments, probably
http://focus.ti.com/docs/prod/folder...t/tlv2374.html
Hi Andy,
Great work with those schematics!!
The eeprom if I understand correctly it is used to store the parameters in order to autoinitialize the drive. For a first test we could just load the parameters from the host computer through serial, am I wrong?
I could probably mill some boards up to two layers and solder the igbt module, irmck210, etc... for a first test. I already have all the irf ICs.
Andy could you send me that file in a format that eagle can open? (I am not limited to the free version but I don't have acces to pad)?
Or maybe a board layout of your schematic and I will try to solder a board together.
Last edited by lolailando; 11-30-2005 at 04:44 PM.
iramx: yes, that is what I have drawn there right now. need to find some 3.3V compliant optoisolators to put inbetween irmck and iramx
(slightly OT: found another integrated powerstage alternative, Fairchild FSBB15CH60, chepaer than the iramx at only 14usd and should do the same thing...)
the iramx also needs proper thermal design i.e. a big enough heatsink and probably also a fan.
eeprom: yes that is the idea. testing could maybe be done without an eeprom. I was wondering what the address lines are used for when using only the 2-line interface to the iramck
schematics: I'll see what pads can export. I think we need to spend at least a few weeks thinking about different options and finalizing the design.
pcbs:etching is probably not an option with the 100-pin QFP etc. I'm thinking that we might as well use SMD for most of the components since the irmck is not available as thru-hole.
Most optocouplers do have diode forward voltage of 1.2 to 1.7V. So 3.3V is no problem. It just needs smaller resistor value compared to 5V input.Originally Posted by andy55
BTW, it's really nice to see multiple AC drive projects going on. It will be interesting to see how MCU based design compares to IRMCK based one.
I just got a CNC engraver and I was thinking to mill the PCBs. I have never done it, but I have seen examples on the net. I need to install some software and try milling a couple of them. I am not sure if it will be able to mill that precise, but I am optimistic.
Send me some files with a qfp100 to mill some boards just for testing the engraver at least.
And we will see how they come out
If it works I will mill you some boards
sorry I didn't look good enough to your schematic before posting, I missunderstood your message.
It is nice to have someone start the big step to realize the project. Great job Andy55.
BTW, I think we do not need to isolate the IRMCK from IRMX, becouse IRMX have the insulation it's selft (like IR2137). I think we should insulate the RS-232 out from PC. Correct me if I am wrong.
Regards,
TR2000
Optoisolation might not be necessary at all if a transformer isolated power supply is being used. I think Rutex boards don't have any kind of isolation (correct if I'm wrong). But of course isolation provides protection if something goes terribly wrong.
Hmm. How about those isolated RS-232 adapters sold in many places?
worked a little bit on the schematics today also, see attachment.
I really like the idea of isolating all the HV stuff. It's not nice to blow up computer + motioncontrol card etc. the first time testing the servodrive...
so I have put HCPL optoisolators between IRMCK and IRAMX + IR2175
I also re-named the high voltage ground to GNDHV, it's now separate from logic ground.
a few of my earlier questions were answered, but a lot remains:
- at24 eeprom: what to do with the pins that are not connected
- emi suppression caps for HVDC bus
- as it is now the HVDC-bus sensing (for braking) is not optoisolated in any way. The voltage is coupled thru 2MOhm resistors to the op-amp. maybe that's enough ??
- what to do with the Itrip/Temp output from the IRAMX ?
some trivial stuff that I have not had time to do:
- size of braking resistor + braking IGBT type ?
- RS232 pinout
- regulators: 5V input for logic side, need 3.3V regulator
15V input for HV side, need 5V regulator
- filtering caps for all ICs
- choose OC-sense FET
- size of series resistors for 3.3V driven LEDs (REDLED, GREENLED, HCPL2531 optos) ?
looks like it will fit on a double sided 100x220mm eurocard.
I threw the components in preliminarily... the autorouter finds a solution for double sided pcb (with a lot of vias ofcourse...some erroneously under irmck etc...) see attached JPG.
please don't go off and build something like this, it's just a very preliminary test.
maybe we should change all components to SMD and make it fit on the smaller standard eurocard 100x160mm which all boardhouses seem to quote cheap prices for ?
you will see I have used a bnc connector for the torque command, db9 for rs232, db15 for encoder+hall. 2/3 screw-terminals for DC power and motor.
now I'm thinking maybe I want two db15 connectors for enc+hall, one input for the drive and one output for passing on the signals to motioncontroller.
the rs232 could be a temporary header somewhere in the middle of the card since it is only used for tuning the system.
EDIT: attachments removed, see end of this thread for current version
Last edited by andy55; 12-02-2005 at 03:34 PM.
I think the three pins A1 A2 A3 should go to ground. That's the hardwire identifier for position zero, which I guess should be the default position when using only one eeprom IC. I have looked at the registers and I haven't seen any where any bit that adresses eeprom IC position.
Nevertheless I have emailed irf to check on this. I will post it when I get an answer.
I think all smd is good if it makes the board cheaper. We can allways rerun a new design with through hole components later.
good work andy!!