Abstract: A modular heat-radiation structure includes a module for generating heat, including a first main unit having a heat-radiation fin, fixed to the top face of the first main unit for radiating heat generated in the module and a resin-made and insulating heat shield inserted between the printed circuit board and the first main unit.

Abstract: A modular heat-radiation structure includes a module 5 for generating heat, including a first main unit 5a having a fixing hole 5e and a lead 5L for connecting to the printed circuit board 3, a heat-radiation fin 7, fixed to the top face of the first main unit 5a, for radiating heat generated in the module 5, a resin-made and insulating heat shield 9 inserted between the printed circuit board 3 and the first main unit 5a, and a screw 13 for fixing the heat shield 9, the module 5, and the heat-radiation fin 7, where a lead hole 9L for allowing the lead 5L to pass therethrough and a first fixing hole 9e for allowing the screw 13 to pass therethrough are provided in the heat shield 9, and a second fixing hole 3e for allowing the screw 13 to pass therethrough is provided in the printed circuit board 3.

Abstract: In the pedal assembly of a sewing machine drive device, a potentiometer operating member is guided by a mounting stand secured to the pedal stand, to control the slide shaft of a direct acting type potentiometer, and a speed changing pedal including a depressing board to depress the potentiometer operating member with its one end portion is coupled to the pedal stand with the other end portion. When the speed changing pedal is stepped on, a signal is outputted to change the speed of rotation of the sewing machine according the movement of the pedal thus stepped on. The pedal stand may have an opening with which the pedal is swingably engaged. In addition, signal pedals may be arranged in alignment with the speed changing pedal with the same mounting means provided at the position of those pedals, so as to allow the pedals to swap in position with one another.