IPC Subgroup
H04R 1/42 Combinations of transducers with fluid-pressure or other non-electrical amplifying means
Introduced: September 1968
Last revised: January 2006
Full Title
Details of transducers > Combinations of transducers with fluid-pressure or other non-electrical amplifying means
Classification Context
- Section:
- ELECTRICITY
- Class:
- ELECTRIC COMMUNICATION TECHNIQUE
- Subclass:
- LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS