To: File

From: Jon Hagen

Date: 8-19-99

Subject: Test of Kollmorgen B606 motor for use in the tie-down system

A spare azimuth drive system amplifier, a Kollmorgen BDS4A-220H, was connected in the lab to a spare Gregorian drive motor, a Kollmorgen B606-A-B2-B9S-095. The amplifier was first fitted with a 606 compensation board on which the velocity feedback components () had been replaced. Vertex had removed these components to disable the internal velocity feedback loop. With this restored compensation board, the full model number of the amplifier would be BDS4A-220H\606A2. Attached is the Kollmorgen data sheet for this compensation board.

The amplifier was powered by a PSR4/5A-275 supply, a spare for the Gregorian drive system.

A dual lab supply with a 5k pot supplied a -10V to +10V manual control signal. A hand-held

tachometer measured the speed of the motor shaft. A second lab supply provided 24 volts to release the brake. Primary 3-phase voltage (220V between phases) was taken from a breaker above the cable tray. Other connections were 120VAC for the power supply, a bias voltage jumper cable from the power supply to the amplifier, and a toggle switch to enable the amplifier.

Test results:

Sense of rotation when facing the end of the output shaft: Clockwise for positive differential control voltage.

Control voltage	Speed	Speed Monitor voltage

0V	0 RPM	0

+1.05V	160

+2.04	321

+4.05	638	+3.3

+9.95	1466

-4.00	640	+3.3

-10.06	1484

With the brake applied and the control voltage set at zero, the motor did not move and the current monitor port (pin 18) read only a few millivolts. Increasing the control voltage slightly made only a slight change - the current did not integrate up to any appreciable value. (The op-amp integrator in the Kollmorgen amplifier has a large value resistor shunting the integration capacitor). The control voltage was increased all the way to the full 10 volts. At nearly full control voltage, the motor began to creep, overcoming the brake. At this point, the current monitor voltage read 5.3 volts (Kollmorgen states that a reading of 8 volts corresponds to the peak RMS current rating of the BDS4). No over-current trip occurred.

Control voltages up to +/- 14V produced correspondingly increased speeds without tripping the amplifier's overspeed circuit.