EP 0409429 A3 19920318 - LOUDSPEAKER DRIVE UNIT
Title (en)
LOUDSPEAKER DRIVE UNIT
Publication
Application
Priority
- JP 8548989 U 19890720
- JP 18629089 A 19890719
Abstract (en)
[origin: EP0409429A2] The invention relates to a constant current drive speaker system in which a dynamic speaker is driven by a constant current amplifier. Generally, when the dynamic speaker is driven by a constant current, it is frequently observed that the vibrational system thereof cannot be damped satisfactorily near the low band resonance frequency. To remove this disadvantage, a damping coil (23) provided bodily with the vibrational system is terminated by a predetermined impedance and is provided within a magnetic gap of a magnetic circuit (25) provided independently of the magnetic circuit (15) of the vibrational system, thereby damping the vibration system. Alternatively, a voice coil bobbin is formed of a conductive material to form a short-circuited ring on which there is wound a voice coil. This speaker system is driven by a low frequency, whereby the vibrational system thereof is damped without electromagnetic coupling.
IPC 1-7
IPC 8 full level
CPC (source: EP)
H04R 3/002 (2013.01); H04R 9/063 (2013.01)
Citation (search report)
- [X] US 4598178 A 19860701 - ROLLINS WILLIAM L [US]
- [X] EP 0134092 A2 19850313 - LINN PROD LTD [GB]
- [X] US 4783824 A 19881108 - KOBAYASHI YOSHIHIRO [JP]
- [X] GB 1591184 A 19810617 - ARD ANSTALT
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
DOCDB simple family (application)
EP 90307020 A 19900627