Can anyone suggest a analog amp for me?

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11-06-2010, 12:49 PM
jacampb2

Can anyone suggest a analog amp for me?

I have been working on my servo conversion for about 6 months now off and on, I finished my power supply a few weeks ago, and was going to start bench testing my amps and servos and the first of my 3 amps is shelled. I have two AMC S100A40 amps that are for my X and Y axis, the amp that is bad is a AMC B40A40 and was for my Z axis-- really ticks me off, the amp was an ebay purchase and I never even opened it up when it arrived, now that it is time to go into use it is far to late for any remediation...

Anyhow, point of this is, #1 check your **** from ebay when you get it :) and #2 can anyone recommend a reasonably priced analog brushless amp of the same approximate size? The B40A40 is a 400Vdc, 40 amp max, 20 amp continuous +/-10V control amp. I don't even really know what my options are for larger amps, and there are just to many amps to sift through on the surplus market if you don't know the model designations or at least a manufacturer to start with.

FWIW, I have been watching for another AMC amp, and so far there has been nothing remotely large enough for me.

Thanks in advance for your suggestion!
Jason
11-07-2010, 01:35 AM
Iron-Man

3 AXIS A-M-C PWM Brushless SERVO AMPLIFIER ASSEMBLY NEW

Quote:

Originally Posted by jacampb2

I have been working on my servo conversion for about 6 months now off and on, I finished my power supply a few weeks ago, and was going to start bench testing my amps and servos and the first of my 3 amps is shelled. I have two AMC S100A40 amps that are for my X and Y axis, the amp that is bad is a AMC B40A40 and was for my Z axis-- really ticks me off, the amp was an ebay purchase and I never even opened it up when it arrived, now that it is time to go into use it is far to late for any remediation...

Anyhow, point of this is, #1 check your **** from ebay when you get it :) and #2 can anyone recommend a reasonably priced analog brushless amp of the same approximate size? The B40A40 is a 400Vdc, 40 amp max, 20 amp continuous +/-10V control amp. I don't even really know what my options are for larger amps, and there are just to many amps to sift through on the surplus market if you don't know the model designations or at least a manufacturer to start with.

FWIW, I have been watching for another AMC amp, and so far there has been nothing remotely large enough for me.

Thanks in advance for your suggestion!
Jason

These may not be as powerful, but they are brand new. Found these one late night while on ebay:
3 AXIS A-M-C PWM Brushless SERVO AMPLIFIER ASSEMBLY NEW

Hope this helps,

Iron-Man
11-07-2010, 01:59 PM
jacampb2

Thanks, the link is bad, but I did find it on ebay. The 30A max drives would probably work for this axis, but those are only 80V amps, My supply is 330Vdc. Anyhow, this is what I have been finding too, a bunch of 80V amps, some 200V drives, but nothing close enough for what I need.

Thanks,
Jason
11-08-2010, 12:30 AM
mike_Kilroy

HOW MUCH r u willing to spend?

what is the feedback for this 330vdc (230v ac input) drive?

do u plan single phase 230 or 3 ph input?
11-09-2010, 05:11 AM
jacampb2

Quote:

Originally Posted by mike_Kilroy

HOW MUCH r u willing to spend?

what is the feedback for this 330vdc (230v ac input) drive?

do u plan single phase 230 or 3 ph input?

I'd honestly rather keep the price down and wait vs. spend a lot and get it right now.

Feedback is incremental encoder + halls, but it is not strictly necessary that the drive does the commutation. I am running a Galil card for control and it can do the commutation, I would however prefer that I find another amp that does it's own commutation, if I do sinusoidal command on one more axis then I am going to be one axis short on my control card.

The power supply is already built. I built one DC supply for all three amps. If my only available option is an amp with an internal supply, I can use anything single to three phase 220 to 460 VAC.

Thanks,
Jason
11-09-2010, 01:24 PM
mike_Kilroy

What is the motor part no and/or nameplate ratings? No sense throwing a 40 amp continuous or even 20 amp cont drive at it, if it is only rated 12amp cont.... tell us the actual motor ratings so we can consider the widest range of drives for you. For reference, a Kollmorgen AKD 12amp brand new enc/hall feedback 12a cont industrial servo drive goes for about $1200; a 24a model around 1700. They do have PS internal but can accept ur DC bus if u want also. Also be careful about 460vac to servos; a lot of them are wound for 230vac max; magnet wire varnish will self destruct in minutes if run on 460vac....
11-09-2010, 03:16 PM
jacampb2

The Servos are Nachi MSM302Q2V1 3Kw AC servos, I replaced the serial encoders with Renco incremental + hall tracks. Data sheet say's 200 Vac 18.6 A continuous, 80 A peak. I probably don't need the full torque out of this servo as it is just going to drive the Z axis, so it is possible that I can get away with even a lower current amp than 20A.

Thanks,
Jason
11-09-2010, 04:44 PM
Al_The_Man

What exactly is the problem with the dud ebay amp?
I have returned amps to AMC for repair, although they are not cheap, it may be less than the cost of a replacement amp?
Al.
11-09-2010, 11:45 PM
jacampb2

It either had the ps input cap leak and burn or some nub hooked power up backwards. It is going to need pretty much a new board, there are two spots that are burned nearly through, otherwise I would have taken a stab at fixing it already-- probably still could fix it if I could see what the board layout was, but it to gone for that. I'll see if I can post a picture...
http://tapa.tk/mu/611e4452-cf0f-ad86.jpg

Thanks,
Jason
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11-10-2010, 02:45 AM
mike_Kilroy

eBay.com.sg: AMC Brushless Servo Amplifier B30A40 NEW advanced (item 150406576759 end time Nov 14, 2010 21:44:51 SGT)

eBay.com.sg: AMC brushless servo amplifier BE25A20E (item 310165227459 end time Nov 23, 2010 16:37:31 SGT)

http://cgi.ebay.com.sg/AMC-Brushless...#ht_1956wt_691