【物理】使用交替偏振的直流调节器

direct-current telegraphy

direct-current meter transformer

speed conversion dc telegraphy (direct-current telegraphy)

direct-current telegraphy, compensating variations

direct-current telegraphy work (material) (rolling stock)

direct-current system【电】;straight flow system【航】

alternating current/direct-current

restoring direct-current telegraphy