A device for converting energy form one form to another. In relation to computers, the term is applied to a read/write head, to detector of sector marks in a magnetic disc system, and to electronic/sonic pulse converters of delay line memory.把能量从一种形式转换成另一种形式的装置。在与计算机有关时，这个术语用在磁盘系统中的读／写磁头、扇面标记的检测上，以及用在延迟线存储器的电子或声波脉冲变换器上。
