Bobbin Thread Detector - promelectroavtomat ULT2003D Service Manual

15.

BOBBIN THREAD DETECTOR

STANDARD
When the amount of the bobbin thread has decreased until the bobbin diameter is 11.4-11.8 mm, the message
"Bobbin thread is running out." should appear on the display.
ADJUSTMENT
1. Select test mode No.10 on the touch panel.
2. Turn the balance wheel in its normal rotation direction, align the opening of the outer rotary hook with the
photo diode, and make sure that "0.0" appears on the display.
3. Wind the bobbin thread around the bobbin until the diameter of the bobbin is 11.4-11.8 mm, and set the
bobbin in the inner rotary hook.
4. Loosen the screw holding the photo transistor, slightly adjust the photo transistor to the left until "+.+"
appears on the display. Then adjust it to the right until "0.0" appears on the display, and tighten the screw.
NOTE :Keep the area around the photo transistor and the photo diode clean.
Remove the lamp during the adjustments.
Adjustment Points
1. Remove the needle plate before making the adjustment.
2. After aligning the opening of the outer rotary hook with the photo diode so that "0.0" appears on the
display, the inner rotary hook (A) should contact the bracket while the photo transistor screw (B) is
loosened and tightened so that the photo transistor can be adjusted.
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