P O W E R A M P L I F I E R S
MSA-12-80
Power Amplifiers
87
BRUSH-TYPE
Adjustments
Connectors
The MSA-12-80 has four potentiometers that can be adjust-
ed. The output voltage of each potentiometer is measured
at the respective probe hole in front of the potentiometer.
Potentiometer 1--Loop Gain
CW rotation increases the amplifier gain.
At extreme counterclockwise setting, the gain is 1
Potentiometer 2--Current Limit
CW rotation increases the current limit
Range: 0-10 V, where 10 V give 12 amps continuous
The peak current limit equals twice the continuous limit and lasts
for 2 sec.
Potentiometer 3--Reference Input Gain
CW rotation increases the input gain.
At extreme clockwise setting the gain is 1.
Potentiometer 4--Offset Voltage
The sensitivity of the offset voltage is increased 50 times by
closing SW4.
Range: ±5 V
POWER CONNECTOR; 5-PIN SCREW-TYPE:
1 Motor armature +
2 Motor armature -
3 Power ground
4 Power ground
5 Supply voltage +
SIGNAL CONNECTOR; 16-PIN MOLEX:
1 5 V, 5 mA out (available for customer use, short-circuit protected)
2 Ground
3 -5 V, 5 mA out (available for customer use, short-circuit protected)
4 +Reference input (differential analog input from Galil controller;
±15 V max; 50KW input resistance)
5 -Reference input
6 -Tachometer feedback ±60 V analog signal max; 60KW input resistance
7 +Tachometer ground
8 Current monitor .25 V = 1 A
9 Current command .3 V = 1 A
10 NC
11 Inhibit* (low-level TTL inhibits amplifier; internal pull-up)
12 +Inhibit* (low-level TTL inhibits +half of bridge; internal pull-up)
13 -Inhibit* (low-level TTL inhibits -half of bridge; internal pull-up)
14 Fault out (TTL level; high designates fault)
15 NC
16 NC
* Active low
MSA-12-80 Schematic
