ESD prevention on an unshunted MR head

A magneto-resistive (MR) head is easily damaged by a transient current due to electrostatic discharge (ESD). Often the current is introduced through unshunted leads. The damage can be prevented by two practical methods. First, the potential of a MR head and any bare conductor can be equalized through a large resistor before direct contact. Second, the MR head potential can be reduced capacitively, i.e. through a virtual ground. Several examples are described.