G
PHYSICS
G
PHYSICS
G08
SIGNALLING
G08
SIGNALLING
G08B
SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
G08B
SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
5/00
Visible signalling systems, e.g. personal calling systems, remote indication of seats occupied
5/00
Visible signalling systems, e.g. personal calling systems, remote indication of seats occupied
G08B5/22
using electric transmission; using electromagnetic transmission
G08B5/22
using electric transmission; using electromagnetic transmission