| 摘要 |
The safety unit (1) comprises a coupling component for connection to the object, an oscillation circuit to which the coupling component is connected, a transmitter (5) connected to the oscillation circuit and a receiver (6) also connected to the oscillation circuit. The transmitter and receiver form a loop in which oscillations are produced. The oscillation circuit activates the coupling component to produce a change in condition in the object when oscillation stops. The oscillation circuit comprises a first pulse unit (8) connected to the transmitter and a second pulse unit (11) connected to the receiver. The two pulse units are coupled together via a pulse link (15), and trigger one another by means of trigger pulses, so that a self-oscillation is formed via two signal paths. The one signal path goes via the transmitter and receiver from the first pulse unit to the second pulse unit and the second signal path goes via the pulse link from the second pulse unit to the first pulse unit. |
