变压器设计心得（Transformer design experience）.docVIP

变压器设计心得（Transformer design experience） Transformer design experience 2009/05/26 asdjf@163.com Switching power supply design, the most difficult is the transformer / inductance coil design and manufacture and PCB, Layout and structural shell processing, and other parts may be standard single-chip solution circuit, according to the reference circuit can copy. PCB Layout determines the EMI performance and thermal performance of power supplies, and for those interested in this, see the value-added package series - happy with me, high speed PCB design.. The following is mainly about DIY winding transformer / inductance coil experience. Dear sirsre Transformer principle Dear sirsre When we put the wire into the 220V power outlet, will have a short circuit, but not into the transformer, the difference lies in the primary side of the transformer coil wire is wound on the iron core, just because a core wire short circuit will lose the role? Yes, insert the wire core becomes a inductance coil, according to Lenzs Law: the induced current magnetic field is to hinder the variation caused by the flux of induction current, (Note: the block is not contrary, the original magnetic flux increases in the opposite direction, the original magnetic flux decreases at the same direction; hinder not stop, in the circuit flux or change. The primary side of the transformer) will have an equal and opposite to the direction of the 220V voltage offset input reverse electromotive force, excitation current flowing through the wire only weak (need to have a magnetic field, so the current maintenance) lost wire short circuit effect. If so, how about wrapping a few laps of enameled wire around the nail and inserting the wire into the 220V outlet, is it possible that it wont short-circuit? It must be short circuited. The reason is that the iron core is magnetically saturated and cannot generate a counter EMF that counteracts the input voltage. At this point the wire is equivalent to the short line. Op