IPC Subgroup
H04Q 1/18 Electrical details
Introduced: September 1968
Last revised: January 2006
Full Title
Details of selecting apparatus or arrangements > Electrical details
Classification Context
- Section:
- ELECTRICITY
- Class:
- ELECTRIC COMMUNICATION TECHNIQUE
- Subclass:
- SELECTING
5 direct subcodes
Child Classifications
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- H04Q 1/2 Testing circuits or apparatus; Circuits or apparatus for detecting, indicating, or signalling faults or troubles
- H04Q 1/28 Current-supply circuits or arrangements for selection equipment at exchanges
- H04Q 1/3 Signalling arrangements; Manipulation of signalling currents
- H04Q 1/54 Amplifier switched-on automatically in dependence on automatically selected lines
- H04Q 1/56 Balancing circuitry switched-on automatically in dependence on automatically selected lines