Core for low noise transformer and reactor

摘要

PURPOSE: To reduce the noise of a transformer and a reactor down to a level requiring no noise absorbing member nor noise insulation box. CONSTITUTION: The low noise transformer employs a silicon steel plate having DC magnetostriction between -1.5(1/106 ) and 1.5(1/106 ). The abutting parts of compositional members of the core and, preferably, the parts of the core to be tightened by bolts and the gap part are bonded through an adhesive having the bonding strength of 100kgf/cm2 or above. The laminated steel plates are immersed into varnish to be bonded and a coil is fixed. More preferably, the core is welded in the laminating direction of steel plate. A spacer made of nonmagnetic material having hardness Hv of 50 or above is inserted into the gap depending on the size thereof and the spacer 15 bonded to the compositional member of the core through an adhesive having the aforementioned bonding strength. This structure reduces vibration caused by various factors of the core significantly thus reducing noise effectively.