Gettys servo motor

[KTP]

Hi guys,

Do any of you happen to know the wire color and correct voltage for the hall sensors on a API Gettys Turbo Servo Motor, model MEB-341 ? This is an 8 pole brushless motor with a Renco encoder, but the hall wires are separate from the encoder and come out from the inside of the motor. I am pretty sure this means they are true hall effect sensors and not just encoder tracks, so they might need +/-12V and be open collector transistors.

The 5 wires which I believe are the hall wires are yellow, brown, green, orange and blue. No obvious choice for which ones are power and ground.

The fatter, motor phase wires are black red and white, but I can figure those out with my oscope anyway.

I have scoured the internet and API's website and also Elwood-gettys website, but no luck. I can do a phone call, but would really like to get this spinning today, so I can test my Taig spindle drive (driving the spindle with this motor, hopefully).

Thanks for any help!

[Al_The_Man]

I have a stack of API-Gettys catalogues and it shows all the specs and part number break down on those motors, but does not show any connection diagrams!
The driver/amplifier section only shows commutating encoder or resolver,
The complete part number indicates whether separate Hall effect sensors or encoder/commutation combined.
Al.

[KTP]

Thanks Al.

The Renco encoder which has a gray cable coming out of it seems to be a standard 3 channel incremental type, based on the wire colors.

it has red, black, white, yellow, green, blue, orange, and brown

On the Renco site, I found these exact colors correspond to Vcc, Ground, A, A#, B, B#, Z and Z#.

So that leaves the other bundle of 5 wires, which HAS to be hall sensors (power, ground and the three hall channels).

So what would be the likelihood of damaging the halls if I picked two of the wires and applied a current limited 12V to them and monitored the other three wires on my scope? I don't have any real data on what type of hall chip they would be using...

Oh, the complete part number is MEB-341-YH05-211

[Al_The_Man]

The part Y number indicates rpm, but I show 6 letter options but it goes from N=7000rpm to V=10,000 rpm, the H is Halls and the 05 indicates 2000ppr encoder.
What I would do is use a 5v current limited supply, say 500 ohms, and pick a pair of conductors as +&- and turn the armature over, while monitoring the other three out, when all three appear to switch in turn, you most likely have the three outputs, this is rather crude and may not be conclusive.
I would tend to think they are 3 discrete Hall effect sensors.
Al.

[KTP]

Well, I tested each lead with my multimeter in diode test mode and found identical voltage drop in the blue, orange and yellow leads referenced to the brown lead. Setting the brown lead to 5V through a 100 ohm resistor and the green lead to ground caused a 10 mA current flow and the oscilloscope showed three perfect square wave hall signals on the blue, orange, and yellow leads when i rotate the motor shaft clockwise by hand. Now I just need to check the motor U phase against these to figure out which hall state is which.

Edit: I also used a 10kohm pullup resistor to 5V on each of the three channels.

Thanks

[Al_The_Man]

If you use the motor back feed method to produce the stator sine waves, I usually put a 1k resistor on each phase and connect the other R ends together to produce an artificial star point for the 'scope common.
Al.

[KTP]

I got the motor running fairly well with a AMC amp. It is an 8 pole motor and has a tiny bit of cogging on the trapezoidal amp, but not too bad. It seems to run smooth up to 500,000 steps/sec (3750 rpm) and then has some strange occasional thumping at around 540,000 to 560,000 steps/sec, then is smooth again until about 700,000 steps/sec (5250 rpm) which is about the max I seem to be able to make it go. The nameplate said 7000 rpm max, Vrms/krpm of 17.59 and rated amps of 7.65rms. I was assuming from this that it was rated to run off of an amp powered by 115VAC, which is what I am using.

Anyway, 4000 rpm or so will be fine for inital use on the taig spindle, since I plan to gear it up 2 to 1 at least. I am more concerned with not having excessive vibration...I wish I had an extra sinusoidal amp, but I have them all earmarked for other things (axis drives).

[Al_The_Man]

and then has some strange occasional thumping at around 540,000 to 560,000 steps/sec, then is smooth again until about 700,000 steps/sec (5250 rpm) which is about the max I seem to be able to make it go.

I am in the process of fitting a Renco encoder to Fanuc 8 pole motors, I lined it up initially the static way with DC on the windings, I found that when I ran it on the AMC I got occasional thumping, especially on one direction, The encoders have orientation slots so I found that by moving it a few deg. while running it eliminated the thump.
Al.