For example, the R&S®NGE100B power supplies use a mains transformer at the input, followed by a rectifier and switched-mode circuitry to regulate the output voltage, providing high efficiency. A linear stage reduces unwanted signal components at the output. Another example for mixed achitecture is the R&S®HMP2000/4000. Mixed architecture power supplies 直流电源的象限 如果电流流入正电压端子，电源会变成电子负载。电源不会供电，而是会吸收电能。