Dual 1225 - Motor and Drive

Figve 2
1
Hida
ee
RRS EPR
AGEGOOOOL
CODD BGO
11 104 10 109 126 108 130 152
Fig. 3
Motor suspension and platter drive Dual
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1224
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139 125 156
Motor suspension and platter drive Dual 7225
11 104 10 109 126 108 130 152
Motor and Drive
The platter and associated mechanism are
driven on the Dual 1224 by a two—pole asyn-
chronous motor (125) and on the Dual 1225
by a four-pole asynchronous motor (150).
Both motors have a rotor balanced at two
levels, polished bearing surfaces and en-
Sure vibrationfree running. In addition,
the four-pole motor is distinguished by
an extremely small stray magnetic field.
The speed of the motors is constant over a
supply voltage range of + 10 %. Deviations
in speed depend on, and are proportional
to, the line frequency. Adaptation of the
motor to 50 or 60 Hz power is accomplished
by changing the motor pulley (137/139).
Two-pole motor (Dual 1224):
Pulley for 50 Hz ATG, NOx. 292: 69:6
Pulley for 60 Hz Art. No. 2342897
Four=pole motor (Dual 1225):
Pulley for 50 Hz Art. No. 232 898
Pulley for 60 Hz Art. No. 232 899
137 150 156
The motor pulley is secured to the motor
shaft by a setscrew. When a pulley is re-
placed or exchanged it must be set at the
correct height (see Fig. 4).
The platter is driven by the idler wheel
(152) which is automatically disengaged
From the motor pulley when the unit is shut
off in order to protect its driving surface.
Platter speeds of 33 1/3 and 45 rpm are se-
lected by raising or lowering the idler
wheel (152) to the appropriate step on the
motor pulley.
When the selector lever (33) is moved, the
selector segment (108) rotates. This causes
the lever (130) fitted in the slot of the
selector segment to move in a vertical di-
rection. The idler wheel (152) mounted on
the swinging arm (155) is lifted off the
mator pulley and set down again on the mo-
tor pulley step for the appropriate speed.