Re: Advice on buying servos.
There are a few reasons, but this one normally gives you an indication.
Ok, lets say you have a machine with 8 axis and each axis needs a servo, that is not too large.
you can get 8 AC servo motors and driver and you will be paying more because each driver has its own power supply.
with the DC option, you will have 8 DC servo drivers and a large power supply.
Also DC servo motors are typically low voltage DC, so the current is higher, so typically the motors dont go too big (under a KW)
Personally, i would not even consider a DC servo system, unless you know why you need it. AN ac servo system is typically a better option.
Quote:
Originally Posted by
Agathon
OK, that's a very concise reply, but why buy a DC over and AC and vice versa?
Re: Advice on buying servos.
Quote:
Originally Posted by
Gary
There are a few reasons, but this one normally gives you an indication.
Ok, lets say you have a machine with 8 axis and each axis needs a servo, that is not too large.
you can get 8 AC servo motors and driver and you will be paying more because each driver has its own power supply.
with the DC option, you will have 8 DC servo drivers and a large power supply.
Also DC servo motors are typically low voltage DC, so the current is higher, so typically the motors dont go too big (under a KW)
Personally, i would not even consider a DC servo system, unless you know why you need it. AN ac servo system is typically a better option.
Right, so AC servo drivers aren't typically 240vac SP input then and need a step-down transformer?
Re: Advice on buying servos.
No, AC is AC, regardless of the voltage.
Typically single phase goes up to about 1.5KW
For a hobby machine, its unlikely you will need anything that big.
Even a mill like Bridgeport MDI /Interact can use 750W easily.
Quote:
Originally Posted by
Agathon
Right, so AC servo drivers aren't typically 240vac SP input then and need a step-down transformer?
Re: Advice on buying servos.
Quote:
Originally Posted by
Gary
No, AC is AC, regardless of the voltage.
Typically single phase goes up to about 1.5KW
For a hobby machine, its unlikely you will need anything that big.
Even a mill like Bridgeport MDI /Interact can use 750W easily.
OK, so just to be clear. A 400W AC servo motor would typically be coupled to a driver powered by AC at a voltage less than 240v? So is the power supply simply a step-down transformer or is there more to it?
Re: Advice on buying servos.
it totally depends on what the bus voltage of the motor is.
To make it easy, if and when you buy them get a matched pair with cables, or talk directly to the company and get advise on what they suggest for the application.
Re: Advice on buying servos.
Quote:
Originally Posted by
Gary
it totally depends on what the bus voltage of the motor is.
To make it easy, if and when you buy them get a matched pair with cables, or talk directly to the company and get advise on what they suggest for the application.
Thanks - I'll email you in the next few days.
Re: Advice on buying servos.
Quote:
Originally Posted by
Gary
Personally, i would not even consider a DC servo system, unless you know why you need it. AN ac servo system is typically a better option.
Me too. And honestly valuing my time i will not consider separate PSU but a pure plug and play system.
Re: Advice on buying servos.
Quote:
OK, so just to be clear. A 400W AC servo motor would typically be coupled to a driver powered by AC at a voltage less than 240v?
No, most of the currently available 400w AC servos are 220-240V
Re: Advice on buying servos.
Quote:
Originally Posted by
Ger21
No, most of the currently available 400w AC servos are 220-240V
Nice.
Re: Advice on buying servos.
What do you think of this: http://www.ebay.co.uk/itm/Samsung-RS...-/282340382590
Might it be suitable for my app or am I barking up the wrong tree?