on-off switch

基本解释

instead, it functions as the gene's on-off switch.
相反，它起着基因启动-关闭开关的功能。
Scientists have developed an on-off switch in memory.
科学家已研制出一种记忆开关。
The device (a prototype is about the size of a deck of cards) connects to your TV and cable box, with an on-off switch for volume leveling.
这个设备(尺寸相当于一副扑克牌大小)将你的电视和有线电视盒相连，并且带有一个开关来控制调节音量。
srschina.blog.163.com

So now it's not just that the on-off switch is stuck in off, the brain's no longer capable of engaging in these higher order P-functions.
所以现在看来就不是开关被卡住，大脑已经不再有能力,实行这些高级的人格功能。
耶鲁公开课 - 死亡课程节选
Of course, to turn the on-off switch on is harder when somebody's in a coma.
当然要开启这个开关难度更大,当人陷入昏迷。
耶鲁公开课 - 死亡课程节选
The cognitive structures are still there, but the on-off switch is switched to off.
认知结构仍然存在，只是开关还没有被开启。
耶鲁公开课 - 死亡课程节选

They seem only to care about where the on-off switch is located.
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