servo amplifier

[frankg521]

Hi Ive acquired 2 areotech servo amplifiers and servos i need to know how to get started wiring them just to experiment at first then for my lathe areotech BA20-160

[Al_The_Man]

The manuals should be on the web site, I have them in PDF if you have a problem.
Al.

[frankg521]

Hi Al Thank You very much for the reply..I have the manual....but i don't understand servo motor control. i understand stepper motor. maybe you can point me in some basic direction

[NC Cams]

Industrial servo's are commonly driven with what is commonly called a +/-10 vdc analog control voltage. If yours use this method, they work as follows:

The polarity (+ or -) tells the direction to go which is not unlike your "direction" bit on a step/direction stepper.

The magnitude of the voltage (0 versus 1 versus or 10) tells how fast. Where relatively speaking, a 0.00 volt signal is no speed in either direction and +5 volts is perhaps 50% of the rated speed of the motor assuming that rated voltage is applied at +10vdc or 100%. If the signal is -5 volts, the motor runs at half speed in the opposite direction.

In steppers, you'd throw more pulses faster to make the motor run faster. In a servo, you increase the ON time of the PWM "H bridge" which is driving the motor to make it run faster.

Check out Unitrode/TI. They have some servo control IC's that have appications notes that explain a lot about how servo's work and they feed back speed and/or position signals to the servo controller. I think UC3637 is one that does a good job of explaining.

[frankg521]

Hi NCCams thank for the info i have a CMC 2620 servo and a areotech amplifier do you have a link to help me experment with these two devices

[frankg521]

OK i found this i guess i need a digital controller can anyone elaborate on this

[Al_The_Man]

Hi Al Thank You very much for the reply..I have the manual....but i don't understand servo motor control. i understand stepper motor. maybe you can point me in some basic direction

The hook up is fairly straight forward, if you have the commutation AND encoder option then the three commutation outputs go to the Aerotech drive and the encoder will split off and go to your controller, whatever that maybe, they usually come with a 1000p/rev differential encoder.
If you want to just hook it and and try turning the motor, a ±9vdc drive signal can be made with a 9v battery and a potentiometer to the analogue input.
If you want to search for some info google Brushless DC servo.
And also search quadrature encoder.
Al.

[Al_The_Man]

OK i found this i guess i need a digital controller can anyone elaborate on this

The BA amp is ±10vdc analogue control, not digital, you can get highend controller cards or CNC systems that use this method (ANALOGUE) or if you use the common hobbiest method of step & direction through the parallel port, Mach etc, you will need a step/dir to analogue convertor. There is one used in the forums here, the name escapes me at the moment.
Al.

[Al_The_Man]

i have a CMC 2620 servo and a areotech amplifier

I have to make a correction, in your original post you mentioned you had Aerotech drives AND motors, but if you have the BA Brushless DC amp and a CMC2620 motor, IIANM this is a DC brushed motor, if so you will have to set the BA for 60° commutation and just use the U V outputs on the drive.
It works fine in this mode as a DC brushed amplifer/drive.
Al.

[NC Cams]

There is this neat tool called Google that doesn't require much input to tell you what you want/need to know.

In this cae, simply by typing in "CMC 2620 servo", the following came up right away:

http://www.cmccontrols.com/brush_ser...atform2600.asp

Go down about 2/3 the way of the page.

For "areotech" the same google search via "areotech servo amp" yielded:

http://www.aerotech.com/products/amps/4020order.html

You should be able to dowload what you need to figure out what you want/need to know.

Just be sure to choose the correct amp that matches what you have and, providing it matches your servo and control scheme input, you should be able to experiment enough to make the motors rotate in a predictable direction.

[Al_The_Man]

http://www.aerotech.com/products/amps/4020order.html

The Aerotech link is for a DC amp, I think Frank has a the Aerotech BA20 DCBL/DC amp & a DC motor, slightly different animal, but I have them working with CMC motors with no problem.
You just do not use the commutation feedback.
In the 60° mode, U & V act as a typical H bridge DC drive.
Al.

[Al_The_Man]

Hi Ive acquired 2 areotech servo amplifiers and servos i need to know how to get started wiring them just to experiment at first then for my lathe areotech BA20-160

Here is a usefull engineering reference for hook up etc.
http://www.a-m-c.com/download/docume...l/engnotes.pdf