Lambda Electronics 71 Instruction Manual - page 21
3. Separate the assembly from panel by
unscrewing of the four phillips head
screws holding the unit to the front
panel.
4. Powerstat and precision potentiometer
assembly may now be separated from
panel.
b) REPLACEMENT OF POWERSTAT OR PRECISION
POTENTIOMETER.
1. Remove powerstat potentiometer assembly
from the equipment as per (a) above.
2. Loosen the set screws holding the flexible
coupling between the two units.
3. Loosen the nut securing the powerstat
to the bracket and remove the powerstat.
4. Replace the powerstat if required, insuring
that at the extremes of rotation of the
potentiometer shaft, the powerstat brush
takes symmetrical positions with regard
to the mounting screw in the rear of the
powerstat.
(NOTE: At no time should the stop collar screws
of the potentiometer be loosened and the collar
moved with regard to the potentiometer shaft.
These set screws are set hard and should remain
untouched.)
5. If the potentiometer is to be replaced,
after removal of the powerstat, loosen
the three pan head phillips head screws
securing the potentiometer to the bracket.
Replace the potentiometer with the new
unit. Refer to Lambda Part No. RW—559V
when ordering. Before tightening the
screws securing the potentiometer to the
bracket estimate the center to center
distance between the shaft of the
potentiometer and the stop screw in
the spacer plate. This is best done
with a pair of calipers. This distance
should approximate 29/64. The powerstat
should now be remounted, and the Millen
coupling joined to the powerstat and
potentiometer shafts. Rotation of the
potentlometer should now be tried and
the Millen coupling should be adjusted
so that at the extreme clockwise and
counter-clockwise positions of the shaft,
the brush holder of the powerstat should
take symmetrical positions with regard to
the mounting screw in the rear of the powerstat.
19.