A control circuit of an interleaved PFC power converter according to the present invention comprises a master switching control circuit, a slave switching control circuit, and a slave reference signal generator. Thus, based on the printing results obtained by a printer, the user can observe the same image as the image on which a tint block image is actually printed. The bar code reader 110 has a operation unit 111 which converts bar codes successively read by a scanner 116 into divisional information, connects the divisional information, and restores the divisional information into transfer information. % of Fe2O3; and adding to the slag a lime source optionally with silica andor alumina, so that the slag, after tranformation and at room temperature, has a propotion of Fe2O3 of less than 13 wt. The coil assembly further comprises a heat dissipating shifted outer jacket made of non-magnetic material snug fitted over the high voltage winding. The inner surface may also include a beveled edge and the arms may have convex or concave end portions.