using electric transmission

Full Title

Systems for signalling characterised solely by the form of transmission of the signal > using electric transmission

Classification Context

Section:

PHYSICS

Class:

SIGNALLING

Subclass:

SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS

Scope Notes

Application references: Signalling arrangements in selecting apparatus (using pulsed current, DC current, AC current or induced current) In selecting arrangements wherein two or more subscriber stations are all directly connected to the exchange, i.e. party-line system, signalling (by pulses, by continuous AC, by amplitude or polarity of DC or by currents in one or other or both line wires or additional wires)