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tommylight wrote:

In Europe you can get toroidal transformes for any secondary voltage, that is the easy part, the 5.4A rating is most probably the long term current the motor can withstand, peak current will be much higher so the drives are usually 20A or 30A rated, hence the power supply must be rated accordingly, in your case at a guess at least 60A transformer and rectifier. Or have 2 of the big motors on one power supply and 4 smaller on another power supply, at 30A to 40A each are easier to manage and find and might even be cheaper. You might easily make do with much less as it is a small weight, and use moderate accelerations.
Does the control box have power info on it? Should be in KW,
 

Yes, two toroid supplies might be the best solution.  Note that these transformers can be overloaded for short intervals, and that the PWM servo amps are switching power supplies, so that power input is just a little over power out, so they can deliver large output currents when the motor is moving slowly, while drawing MUCH smaller current from the DC supply.
Jon

greg23_78 wrote:

ok, so the 160 V on your website corresponds to a peak voltage?
For the input voltage, for reasons of economy, a DC power supply to manage the 6 motors is likely to be expensive.
What's more, being in Europe, I have to manage with 240/400 volts. It's easier to find an auto-transformer to output 110V and add a 3-phase bridge rectifier with capacitor.
is it possible to supply your amps with RMS voltage?

 

Sorry, I really ought to change that.  The amps won't blow up at that voltage, but you have a high probability of having nuisance trips of the overcurrent fault logic.  So, I really recommend 122 V as the highest DC supply voltage.
for resolvers, is there a way to manage robot position data with batteries (like kuka) without continuously powering the computer with linuxcnc open? because manually homing robot axes could take a long time ..

For the input voltage, for reasons of economy, a DC power supply to manage the 6 motors is likely to be expensive.

A simple power supply can be built with a transformer, rectifier and capacitor bank.  In the US, there are commonly-used "step down transformers" that have split primary and secondary windings.  These can be strapped to give various voltages, and are used in large machine tool controls to provide 120 and 240 V from 480 V mains. These can often be found at scrapyards for the salvage metal price. To get 122 V DC with a capacitor-input filter, you would want about 86 VAC from the transformer.  Possibly this can be arranged with a buck-boost autotransformer before the isolation transformer.  If you can find suitable tranformer(s) surplus, this can be done quite cheaply.  The amps definitely need isolation from the mains, and DC input.

for resolvers, is there a way to manage robot position data with batteries (like kuka) without continuously powering the computer with linuxcnc open? because manually homing robot axes could take a long time ...

Our resolver converters have no way to provide absolute position via quadrature output.  That's one of the reasons why some vendors use exotic absolute encoders.  Also, most robots have gearing on the joints, so the motors make many turns for the full motion range.  Fanuc serial encoders, for instance, report # of full turns from the home position, but need a backup battery..
Homing should not be a huge issue, especially if the robot is placed in a good pre-home stance when LinuxCNC is shut down. LinuxCNC can do a sequenced home procedure where each joint is homed in a specified order to be safe.

Jon