PURPOSE: To enable to insulate between the primary winding and a control winding and also between the primary winding and its starting part of winding by a method wherein a flange-like part is provided on the outer circumference of both end parts of a cylindrical spool, and an isolating wall and a pair of barrier are provided on the outer circumference of the intermediate part.
CONSTITUTION: On the coil bobbin 11 located on the primary side, flange-like parts 22 and 23 are provided on the outer circumference of both end parts of a cylindrical spool 21 wherein a core 13 will be partially inserted, and a pair of isolation walls 24 and 25 are provided on the outer circumference of the intermediate part. At the recess 27 located in the cetner of terminal base 28, barriers 31 and 32 are provided between the flange-like part 22 and the isolation wall 24, and the end part and the intermediate tap part of the primary winding 3P which is wound around the isolation walls 24 and 25 can be brought to the terminal base from the notch 33 of the isolation wall 24 through the intermediary of the barriers 31 and 32, thereby enabling to avoid friction with the primary winding 3P whereon the starting part of winding and the intermediate tap part are wound around successively. The control winding 3b, to be wound around between the flange-like part 22 and the isolation wall 24, is completely insulated from the primary winding 3P by the osilation wall 24 and the barriers 31 and 32.
ONODERA YOSHINOBU
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