Hi,
the DYN2 drives require a DC power supply, so you buy a power supply to go from 110VAC or whatever your local supply is to 70VDC. Easy. Makes the most of the AC supply you've got
and gets you full potential of your servos.The DYN4 have a direct off-line supply. If you applied your local line voltage,110VAC or whatever, the servo drive would only have half it voltage,
so it would still work but in stead of driving the servo to 3000rpm it might run out at 1500rpm. Who wants that sort of rubbish? You didn't pay all that money only to have it get to only half speed:nono:
Most direct off-line AC servo drives like the DYN4's and all of the Delta ones are 230VAC single phase, up until about 2kW then you'll want three phase. Anywhere between 200VAC up
to about 250VAC should work. Certainly I would expect DYN4's to work in any Canadian state...after all it is a Canadian brand. You'll have to fit a 110VAC to 220VAC transformer if you can't
get 220VAC into your shop.
You most certainly have used open loop steppers before, just ordinary steppers. Closed loop steppers have an encoder mounted on the back of the motor and that encoder can
inform the drive of 'where it is'. If the motor misses a step the encoder will not match its commanded position and the drive will insert a few extra steps to 'catch up'. Sounds
great doesn't it!. The manufacturers of closed loop steppers will tell you 'never misses steps, goes faster, more power, more this that on the other thing, all BS.
The problem is that when a stepper is marginally overloaded it will start missing steps, closed loop or open loop doesn't matter, when a stepper gets overloaded its in trouble. The driver of
a closed loop stepper will insert some extra steps, but guess what; the extra steps are just as likely to be missed as any other. A closed loop stepper will try to catch up and even
succeed sometimes. What it can do is recognise when its got too far behind and signal a fault where an open loop stepper would just carry on making an out of shape part.
Closed loop steppers can interpolate between full steps and offer increased resolution over open loop steppers. All-in-all the advantages of closed loop steppers are pretty slim
and in my estimation poor use of your money.
True closed loop performance comes with servos such as the DMM's you've seen.
The downside is that once you buy and use a good servo, it will put steppers, closed loop or otherwise, into the shade and you'll not want to buy another stepper ever again.
Servo 'addiction' is an expensive habit. I find 'God grant me the serenity.......etc' helps, but the addiction is cunning baffling and powerful!
Craig