| 摘要 |
The invention provides an item of signalling equipment 1 in which a circuit 4 for applying supply battery voltage reversals comprises transistors associated with a logic control circuit 5 so as to dispense with the relays conventionally used in such an item of equipment and, moreover, to reduce this equipment's bulkiness. The transistors are used equally to provide battery reversals used as telephone signallings as to inject any type of conventional signallings, such as tones or metering pulses, or of digital signallings, such as messages, for novel uses in the subscriber's home. <IMAGE>
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