For an implanted artificial heart system, it is a serious problem to obtain a thin transformer transmitting electrical energy from outside the body. This paper reports a new transformer utilizing amorphous magnetic fibers. The transformer is characterized by its flexibility. The analysis shows that a long, narrow magnetic core is advantageous for a core implanted inside the body. The transcutaneous transformer made as a trial can transmit electrical energy of 20 W continuously. The temperature rise based on the iron loss of the amorphous fiber is negligible up to a frequency range of 100 kHz.
