coil system composed of superconducting and non-superconducting coils with the superconducting coils usually on the outside, trafosüsteem, mis koosneb ülijuhtivatest ja mittejuhtivatest poolidest/mähistest, mille ülijuhtivad mähised on tavaliselt väljaspool, differential coupler comprising a transformer with several windings, diferentsiaaltrafo, mis koosneb mitme mähisega trafost, type of directional coupler which is designed to be configured as a circuit having four ports that are conjugate in pairs, implemented using one or more transformers