A-M-C's S100A40-- I screwed up I think

[jacampb2]

I recently bought two of these amps on ebay, they were dirt cheap, so I am not out much if I can't use them. I thought they were analog +/-10V command, but it seems I misinterpreted the data sheet and they are sinusoidal command. I had planned to go with the YAPSC:10V step/direction--->analog converter to drive the amps via mach3, but it seems that will not be possible.

Is this a total loss, or is there a step/direction---->sinusoidal controller out there that I might be able to use. Preferably something affordable, or the drives are pretty much useless as I can get +/-10V command amps for reasonable price as well...

Thanks for any info you can provide.

Sincerely,
Jason Campbell

[Al_The_Man]

They are usually cheap because they are sinusoidal command, some motion cards such as Galil have this feature available to drive them.
The sinusoidal command allows very economic design of the drive.
Unfortunately I don't think there is a way to use them any other way.
Al.

[jacampb2]

Cool, no big deal, I have plans for the IGBT's in another project if these were a lost cause.

Thanks,
Jason

[Al_The_Man]

Unfortunately you do not see the B100A40's listed very often, I just scored three B100A40AC's for $165.00 ea! They sell for over $1800.00 ea.
The brushless can run brushed or DCBL motors.
Al.

[jacampb2]

Good to know, I don't need anywhere near the 100A peak current rating, but when I saw these I figured they could handle almost anything I could throw at them. I gave $50 each, so like I said, it was really cheap!

Later,
Jason

[jacampb2]

On a side note, I bought some Nachi 3Kw servos off the bay too. They finally got here today, and the name plate does not list the rated voltage or current. I can't find a single data sheet for any Nachi servos online-- any idea who made them or how I might go about getting more info on them. The model number is MSM302Q2V1 if anyone can help. I assume they came from a Nachi robot, and are just house branded since it seems that they don't have any kind of servo offerings independent of their automation.

Thanks,
Jason

[jacampb2]

Bellow are some pictures of the servo and the encoder/halls. I can't find anything on the encoder yet, the only numbers on it are MFE0011BOMA * 04080068N. It is definitely an optical encoder in there, but I have no idea if it is incremental or absolute. I have the wiring colors if they happen to be standardized and anyone can help me...

I have figured out the actual servo wiring, the RED, WHITE and BLACK leads are the three phases, the two small yellow are 24Vdc brake, and the small blue wires are thermal switch. The greed is earth. I suspect the encoder is going to be more of a *****.

Question on determining motor voltage for rated RPMs. I have heard this method will work with a DC brushed motor, but will it work for a AC servo? The method is to spin the servo at 3K rpms and measure the voltage produced. Since they rotor has permanent magnets, I suspect it will work for a AC motor too, but thought I would ask before I tried it.

Here are the pictures, if anyone can come up with more data, or point me in the right direction I would be forever indebted!


Thanks,
Jason

[Al_The_Man]

The method will work with AC servo's, measure between two phases, rotate at a known rpm.
If it was a absolute encoder it would most likely have around 12 conductors + 2 for the power and 3 for the hall effect.
With a bit of reverse engineering of the encoder should turn up the colour code.
Once the power cond. are identified it should be relatively easy!.
Al.

[jacampb2]

Well, I have eleven total leads into the encoder housing. I would be absolutely stoked if these things have incremental encoders. Makes life simpler. Out of curiosity, is the motor wiring colors standardized? I was surprised to find that my actual motor leads match up to the color coding for Sanyo-Denki. Does that tell me that perhaps the motor was made by them, or just that there is a color standard.

Sorry for all the stupid questions. I am pretty new to this, but I am starting to get a handle on it.

Thanks,
Jason

[Al_The_Man]

Unfortunately there is no standard colour code, it might be a guess that Red & Black or the 5v power.
Usually the power can be obtained from the continuity to IC power pins.
11 conductors could put it at 2 pwr, 6 encoder, 3 hall.
Al.

[jacampb2]

So, I managed to get out to the shop today and do a bit more testing. I spun one of the servos on the lathe and measured AC output phase to phase. The lathe has a 7.5HP spindle motor and tops out at 1500 RPMs, and it couldn't get the servo up to that speed-- blows my mind because it is a pretty good sized lathe...

I ended up testing them at 1050 RPMs, which is 35% of their rated speed. I got just over 35Vac RMS between phases. Multiplied by 2.857, that comes out to 100Vac at 3000 RPMs. Am I on the right track? That means for the servos to hit there full rated 3Kw output I need 100V, 30A, or is there and efficiency factor I need to figure in?

As for the encoders and hall sensors, is there any reason that I cannot remove them from the shaft so I can take it down to my electronics lab and try to decipher it, or is it at a precise angular location on the shaft and should not be disturbed?

Thanks for all the help so far!
Jason

[Al_The_Man]

I would initially create a simple AC power supply across the 120VAC single phase outlet, this is all there is in a AMC AC version anyway.
This way you can confirm the rpm at a certain voltage.
If the rated voltage is 100v, you need at LEAST 10% higher than this for the supply.
If you remove the encoders you have to realign them with a double beam scope when reinstalling, I have the procedure in previous posts, or I you need it I can post it again.
Al.