调压自耦变压器

down-regulating；down-regulation

self-regulating

feedback arrangement, internal with particular characteristic in regulating systems

pressure regulating valve

alternating current/voltage regulation using transformer regulating in quadrature

P.D. regulating device with centrifugal governor, exerting an acceleratory effect

self-regulating arc welding transformer【电】

speed governor (speed regulator, speed-regulating device)