H
ELECTRICITY
H
ELECTRICITY
H04
ELECTRIC COMMUNICATION TECHNIQUE
H04
ELECTRIC COMMUNICATION TECHNIQUE
H04Q
SELECTING
H04Q
SELECTING
H04Q1/00
Details of selecting apparatus or arrangements
H04Q1/00
Details of selecting apparatus or arrangements
H04Q1/18
Electrical details
H04Q1/18
Electrical details
H04Q1/30
Signalling arrangements; Manipulation of signalling currents
H04Q1/30
Signalling arrangements; Manipulation of signalling currents
H04Q1/50
Conversion between different kinds of signals
H04Q1/50
Conversion between different kinds of signals