| Patents for H03F 99 - Subject matter not provided for in other groups of this subclass (812) |
|---|
| 11/04/2004 | WO2004095690A1 Amplifier arrangement and distributed audio system |
| 11/04/2004 | CA2522495A1 Amplifier arrangement and distributed audio system |
| 09/23/2004 | WO2004082324A2 Transducer asembly with modifiable buffer circuit and method for adjusting thereof |
| 09/16/2004 | US20040179703 Modifiable buffer circuit for miniature microphone applications and method of adjusting thereof |
| 09/16/2004 | US20040179702 Transducer assembly with modifiable buffer circuit and method for adjusting thereof |
| 09/09/2004 | US20040175007 Semiconductor integrated circuit and amplifier for suppressing pop sound while minimizing voltage transition settling time |
| 08/05/2004 | US20040150477 Amplifier for alternating signals superimposed on a continuous signal and method for amplifying such signals |
| 07/29/2004 | WO2004064026A2 Circuit and method for providing an auto-off and/or auto-on capability for an audio device |
| 07/22/2004 | US20040142718 Mobile communication terminal having a three-dimensional surround sound effect and its control method |
| 07/21/2004 | EP0962120B8 High-fidelity and high-efficiency analog amplifier combined with digital amplifier |
| 07/01/2004 | US20040125968 Monolithic class D amplifier |
| 05/19/2004 | CN1497839A D类放大器 Class D Amplifier |
| 05/19/2004 | CN1150799C High-fidelity and high-efficiency analog amplifier combined with digital amplifier |
| 05/06/2004 | DE10347293A1 Klasse D-Verstärker Class D amplifier |
| 05/05/2004 | CN1148870C Parallel-stage power amplifier and its method for amplifying signal |
| 04/21/2004 | CN1147207C Loudspeakers |
| 04/08/2004 | US20040066229 Class D amplifier |
| 03/03/2004 | EP0962120B1 High-fidelity and high-efficiency analog amplifier combined with digital amplifier |
| 03/03/2004 | EP0941575B1 Efficient parallel-stage power amplifier |
| 02/18/2004 | CN1476667A Power amplification for parametric loudspeakers |
| 02/03/2004 | CA2273858C Power supply for microphone |
| 12/04/2003 | US20030223601 Electronic apparatus having audio output units |
| 11/27/2003 | US20030219135 Acoustic drive circuit |
| 11/27/2003 | US20030219134 Audio control device |
| 09/25/2003 | US20030179893 Presence control for guitar amplifier |
| 09/11/2003 | US20030169177 Method and apparatus for boosting an audible signal in a notification system |
| 07/31/2003 | US20030142834 Headphone amplifier |
| 06/26/2003 | WO2003052925A1 Bicmos ac filter circuit |
| 06/25/2003 | EP1320927A2 Power amplification for parametric loudspeakers |
| 06/12/2003 | US20030108215 Frequency threshold audio activity detector |
| 05/14/2003 | EP1212831B1 Impedance adapting amplifier device for low frequency with electronic tubes insertible on line in the path of the low frequency signal |
| 04/30/2003 | CN1414632A Double-usage of integrated circuit tube pin and signal switch over on the pin |
| 04/24/2003 | US20030076967 Microphone preamplifier |
| 04/16/2003 | EP0870361B1 Efficient parallel-stage power amplifier |
| 04/10/2003 | US20030068052 Dual use of an integrated circuit pin and the switching of signals at said pin |
| 04/09/2003 | CN1409484A Amplifier for alternating signal overlapped on continuous signals and its amplifying method |
| 04/03/2003 | US20030063761 System for distributing a signal between loudspeaker drivers |
| 01/09/2003 | WO2002073792A3 An electret condensor microphone preamplifier that is insensitive to leakage currents at the input |
| 12/12/2002 | US20020186853 Differential audio amplification system |
| 11/27/2002 | CN1382321A Impedance adapting amplifier device for low frequency with electronic tubes insertible on line of path of low frequency signal |
| 11/21/2002 | US20020172380 Impedance adapter preamplifier device for electronic tube audio frequencies able to be inserted on line on the path of the low frequency signal |
| 11/21/2002 | US20020172371 Method and system for automatically detecting and powering PC speakers |
| 11/20/2002 | CN1380744A Controller of radio-frequency power generator for reducing sensitivity to cable length |
| 10/31/2002 | US20020159609 Audio power amplifying apparatus and method |
| 10/23/2002 | CN1375926A Audio-frequency power amplifier apparatus and method thereof |
| 10/09/2002 | EP1248363A2 Controller for RF power generator with reduced cable length sensitivity |
| 09/19/2002 | WO2002073792A2 An electret condensor microphone preamplifier that is insensitive to leakage currents at the input |
| 09/18/2002 | EP1241780A2 Audio power amplifying apparatus and method |
| 09/12/2002 | US20020125949 Electret condensor microphone preamplifier that is insensitive to leakage currents at the input |
| 07/30/2002 | US6427015 Power supply for microphone |
| 07/17/2002 | EP1142448B1 Motor vehicle audio system |
| 07/09/2002 | US6417732 Controller for RF power generator with reduced cable length sensitivity |
| 06/13/2002 | WO2002005588A3 Power amplification for parametric loudspeakers |
| 06/12/2002 | EP1212831A1 Impedance adapting amplifier device for low frequency with electronic tubes insertible on line in the path of the low frequency signal |
| 05/28/2002 | US6396933 High-fidelity and high-efficiency analog amplifier combined with digital amplifier |
| 04/16/2002 | US6373955 Loudspeakers |
| 02/20/2002 | CN1079612C Efficient parallel-stage power amplifier |
| 01/17/2002 | WO2002005588A2 Power amplification for parametric loudspeakers |
| 01/17/2002 | CA2414491A1 Power amplification for parametric loudspeakers |
| 12/19/2001 | EP0818122B1 Improvements in or relating to loudspeakers |
| 11/22/2001 | US20010043652 Digital pulse-width-modulation generator |
| 10/25/2001 | US20010033667 Audio circuitry for dynamics reduction |
| 10/11/2001 | DE10015833A1 Low frequency circuit for dynamic limiting in audio system uses a pair of non linear input stages |
| 10/10/2001 | EP1142448A2 Motor vehicle audio system |
| 08/08/2001 | EP1122973A2 Digital pulse-width-modulation generator |
| 05/16/2001 | EP0943225B1 Power supply for microphone |
| 03/22/2001 | WO2001020777A1 Impedance adapting amplifier device for low frequency with electronic tubes insertible on line in the path of the low frequency signal |
| 10/26/2000 | WO2000038476A3 Motor vehicle audio system |
| 10/04/2000 | CN1269066A Efficient parallel-stage power amplifier |
| 06/29/2000 | WO2000038476A2 Motor vehicle audio system |
| 06/21/2000 | DE19858836A1 Vehicle audio system has separate amplifier for low audio frequencies supplied with significantly higher operating voltage than amplifier(s) for other audio frequencies |
| 06/20/2000 | US6078214 High efficiency class DB power amplifier |
| 12/08/1999 | EP0962120A1 High-fidelity and high-efficiency analog amplifier combined with digital amplifier |
| 11/16/1999 | US5986507 Current mirror circuit |
| 10/26/1999 | US5974041 Efficient parallel-stage power amplifier |
| 10/26/1999 | US5973368 Monolithic class D amplifier |
| 09/22/1999 | EP0943225A1 Power supply for microphone |
| 09/15/1999 | EP0941575A1 Efficient parallel-stage power amplifier |
| 07/14/1999 | CN2329012Y Isolated amplifier for monitoring DC power supply equipment |
| 05/26/1999 | CN1217864A High-fidelity and high-efficiency analog amplifier combined with digital amplifier |
| 02/16/1999 | US5872481 Efficient parallel-stage power amplifier |
| 01/27/1999 | CN1206515A Efficient parallel-stage power amplifier |
| 10/14/1998 | EP0870361A1 Efficient parallel-stage power amplifier |
| 08/27/1998 | WO1998037731A1 High-fidelity and high-efficiency analog amplifier combined with digital amplifier |
| 06/18/1998 | WO1998026631A1 Power supply for microphone |
| 06/18/1998 | WO1998026503A1 Efficient parallel-stage power amplifier |
| 04/29/1998 | CN1180470A Improvement in or relating to loudspeakers |
| 04/22/1998 | CN1179862A Audio bass speaker driver circuit |
| 01/28/1998 | EP0821241A2 Lock-in amplifier with selectable phase selectivity |
| 01/14/1998 | EP0818122A1 Improvements in or relating to loudspeakers |
| 11/13/1997 | DE19629555C1 Lock-in amplifier with selectable phase selectivity for very small and distorted signals |
| 07/10/1997 | WO1997024800A1 Efficient parallel-stage power amplifier |
| 10/03/1996 | WO1996031086A1 Improvements in or relating to loudspeakers |
| 09/29/1992 | US5151663 Plasma switch devices |
| 06/26/1991 | EP0434048A2 Compact high voltage power supply |
| 04/16/1991 | US5008798 Compact high voltage power supply |
| 03/31/1987 | US4654776 Cut-off amplifier |
| 03/03/1987 | CA1218697A1 Compact voltage multiplier for spray guns |
| 12/30/1986 | US4633188 Mixer/amplifier circuit |
| 11/12/1986 | CA1213948A Gain amplifier |