back connected switch

基本解释

You should assume that controller A (left side when looking from the back) is connected to the SAS switch in bay 3 and controller B is connected to the SAS switch in bay 4.
应该假设控制器 A（从机器背面看，在左边）连接到 bay 3 中的 SAS 交换机，控制器 B 连接到 bay 4 中的 SAS 交换机。
Such a reversible-current two-quadrant converter can be realized by two back-to-back connected line frequency thyristor converters or by mean of a switch-mode converter as shown in Fig. 1-5B-2.
这种电流可逆的两象限变流器可以用两个背靠背的工频晶闸管变流器或者如图1-5B-2所示的开关型变流器来实现。使用这种开关型的整流器作为公用电网和驱动器的接口更为合适；

The roof is connected by an elongated bicycle chain to a garage-door motor that rolls it back at the flick of a switch.
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