| 摘要 |
<p>Dental apparatus having a plurality of dental instruments, holders for the instruments, signal transmitters each operable to transmit an extraction signal when an instrument is extracted from its holder, and a logic-actuation circuit for each instrument connected to a respective signal transmitter and to all the other logic-actuation circuits. Each actuation circuit can generate an actuation signal for its associated instrument, and a blocking signal for supply to the other actuation circuits, when an extraction signal is transmitted and when no blocking signal is supplied by any of the other actuation circuits. A single connecting line interconnects the actuation circuits to transmit blocking signals therebetween, and logic identification circuits associated with the actuation circuits are each connected to the connecting line and to an input and to an output of the associated actuation circuit. Each identification circuit is operable to transmit, to the input of its associated actuation circuit, a blocking signal which may be present in the connecting line when an actuating signal is absent from the output of the actuation circuit.</p> |
