D12 is a DC reference voltage output which serves as an AC ground.
D12 is a DC reference voltage output which serves as an AC ground.
D12是直流输出电压，它起一个交流（AC）地（的作用）。
D12 is a DC reference voltage output which serves as an AC ground.
D12是直流输出电压，它起一个交流（AC）地（的作用）。