| 摘要 |
<p>Arrangement in a telecommunication system for random choice of one of a number of selectable devices, the condition of which is marked by the condition of a marking wire connected to the respective device. The selection is made by a selector chain consisting of a number of selector circuits each connected to its own wire. Activation of one of the circuits in the chain prevents the other circuits in the chain from activating, in order to cause that only one device at a time can be choosen. Each selector circuit contains a logic circuit with bistable characteristics. To the input of each selector circuit is connected a gate circuit which is activated on a first input by a signal from a marking wire and on a second input by a pulse from a pulse oscillator individual for each gate circuit. The pulse oscillators are working on slightly different frequencies and thus delivering signals at different moments. When the gate circuit is activated, said signal from the marking wire is forwarded to the selector circuit. That one of the selector circuits which first has received said marking wire signal will then be choosen and the device associated with said selector circuit will be occupied. The random choice is determined by a combination of the time for the call and by the moment in which a pulse from a pulse oscillator occurs.</p> |
