A PCD insert comprises a PCD element joined to a cemented carbide substrate at an interface. A numerical control section outputs an interrupt signal to a sequential processing section upon receipt of an interrupt of start of a control processing period. The peripheral area is disposed around the element configuration area. The second buffer layer may also have a plurality of strength members embedded in it and longitudinally disposed around the optical fiber. The inductor is particularly useful at operating within the radio frequency range and greater.