Re: [CAD_CAM_EDM_DRO] Re: How to connect Rutex drive to Gettys DC servo controller?

Juha Keisala wrote:

>Thanks Jon,
>
>A power source is connected direcly to thyristors??? likewise the
>output to motors with a wire thick as a little finger.
>
>

Well, AC LINE sounds like the power input.

>On the drive it is written SCR SERVO CONTROLLER, does this mean a
>thyristor controller?
>
>

Yes, VERY old servo amps were made using thyristors. SCR is another
name for the thryristor trademark (GE, I believe). They generally had very
low bandwidth.

>Could you exlain the terminal 14 connection again, I did not get it.
>First of all, what is an armature in this case, where exacly the
>armature should be connected to and when? Do you mean the winding in
>the rotor that should be shorted with a resistor, but when? Do you
>mean when turning of the auxiliary of the controller or??
>
>

I have no idea. I am totally guessing. You asked what wire to hook where,
based entirely on the labels on the cabinet. I made educated guesses,
but they
are just guesses. The moving part of a DC brush motor is called the
armature.
To bring such a motor to a stop, a resistor can be placed across it. I was
guessing that the DB relay was for dynamic braking when the drive was
powered off or E-stop was pushed. The resistor should be connected
across the two motor terminals when this condition happens. I was guessing
that the relay would be wired to connect the resistor when the relay coil
was powered off, as a fail-safe mechanism. That is entirely a GUESS.

>How about therminal 11. Should I leave the tachometer into the motor
>and leave it connected inspite of the encoder I have to add for the
>Rutex?
>
>

The amp, if it is a velocity servo, needs the tachometer to measure
velocity.
It would have no use for a tachometer if NOT a velocity servo. If the
original
motors had a tachometer, then the amps need this without reconfiguring them.

>Terminals 5, 13 and 17 are conneted to each others with external wire.
>I'll try to find out is no. 5 in or out
>
>

I really think there is little chance of this working without further
documentation. The performance of such amps is likely to be pretty
bad. The Rutex adaptor may not even be able to be tuned for stable
operation with a servo amp of such low bandwidth. And, if it is as
you say with thyristors wired directly between the line and the motor,
the safety concerns are quite serious. Maybe it requires an external
transformer for isolation.

Jon