NEW TYPE MICROCLOTH-INDUCTOR AND TRANSFORMER WITH THIN AMORPHOUS WIRES AND MULTITHIN COILS

In this paper, we report miniaturization in size along with high resonant frequency and high quality factor in a wide frequency range of cloth-inductor and high coupling coefficient and current capacity in a cloth-transformer. To reduce the eddy current loss of the magnetic core ultra-thin amorphous wires are made by chemical etching. These wires are bounded by multi-thin exciting copper wires of 15-50-mu-m in diameter. The number of cores and windings of coils are varied in the range of 3 to 5 and 7 to 30, respectively. A piece of core is a bundle of 100 or 400 Co-base amorphous wires of 30-mu-m and 5-mu-m in diameter, respectively. The cloth-inductor with 3 cores is a bundle of 400 amorphous wires of 5-mu-m in diameter and the coil is a bundle of 6 copper wires of 20-mu-m in diameter shows inductance of 1.2-mu-H. The Q is higher than 20 in the frequency range from 1 to 20MHz. The maximum of Q (Qmax) is 40 at 5MHz. Its size is 1 x 1 x 0.3mm3. These multi-thin coils inductors are easily modified to make a transformer. Its coupling coefficient and current capacity are 0.95 at 8MHz and 190mA, respectively.