Patents
Sitemap › H01 - Basic electric elements › H01F - Magnets; Inductances; Transformers; Selection of materials for their magnetic properties › H01F 29 - Variable transformers or inductances not covered by group
Patents for H01F 29 - Variable transformers or inductances not covered by group (3,889)
11/1996
11/27/1996EP0744757A1 D.c. reactor
11/12/1996US5574418 Three-phase autotransformer with a balancing function
11/12/1996US5574410 Impedance matching network
11/05/1996US5572170 Electronically tuned matching networks using adjustable inductance elements and resonant tank circuits
10/1996
10/24/1996DE19518272C1 Tap-switch for transformers
10/16/1996EP0737989A1 Switching power supply using a saturable inductor for achieving a pulsed current source
10/12/1996CA2173817A1 Switched-mode power supply using a saturable inductance for producing a pulser current source
10/10/1996DE19523352C1 Current monitoring device e.g. for electric conductor in on-load tap-switch
10/08/1996US5563778 Uninterruptible power supply system
09/1996
09/19/1996DE19509744A1 Stage switches load changer switchover arrangement
09/11/1996EP0640241B1 Step switch
08/1996
08/28/1996CN1129842A Automatic regulating voltage and phase transformer with large power thyristors
08/20/1996US5548830 Dual-band frequency-selective attenuator for automatic gain control
08/13/1996US5546065 High frequency circuit having a transformer with controlled interwinding coupling and controlled leakage inductances
08/08/1996WO1996024146A1 Device for voltage control
08/08/1996DE19543249A1 Tap-changing voltage regulator esp. for discharge-lamp street lighting
08/08/1996DE19541341A1 Tap-changing voltage regulator esp. for discharge-lamp street lighting
08/07/1996EP0725470A1 Phase-shifting transformer and protection system of phase-shifting transformer
07/1996
07/31/1996EP0724275A1 High-voltage transformer equipment
07/23/1996CA2064446C Variable impedance transformer
07/11/1996DE19508267C1 Switch-over device for load changeover switch of stage-selection switch
07/03/1996CN1125891A Choke and making of same
06/1996
06/26/1996CN2230063Y Slip regulating frequency and sense rheostat
06/20/1996DE19501529C1 Stepping transformer load switching device
06/13/1996WO1996018198A1 D.c. reactor
06/04/1996US5523673 Electrically controllable inductor
06/04/1996US5523535 On-load tap changer
05/1996
05/29/1996EP0714106A1 Tunable inductance element, matching network and plasma processing system using such inductance elements
05/28/1996US5521810 Rectifying saturable reactor
05/15/1996EP0712140A2 Tap changer
05/15/1996EP0711450A1 Planar transducer
05/14/1996US5516992 Transformer tap changing and step switch assembly
04/1996
04/03/1996CN1119779A High-frequency choke oil
03/1996
03/20/1996EP0641482B1 Arrangement for generating the ignition voltage for thyristors
03/19/1996US5500582 Multiphase load control system with switch connected split sources of phase voltage
03/06/1996CN2221822Y Inductance automatic regulating reactor
03/06/1996CN2221821Y Two-phase or single-phase load voltage-regulating three-phase transformer
02/1996
02/28/1996CN2221256Y Exciting-free shunting switch
02/14/1996CN2220116Y Load tap switch oil box
02/01/1996WO1996003018A1 Electrical power control system
01/1996
01/03/1996EP0690464A1 Gas insulated tap changer
12/1995
12/27/1995CN2216293Y Dry vacuum load shunt switch
12/21/1995DE4437143C1 Step selector for tap-switch on tapped transformers
12/07/1995WO1995033270A1 Electric adjuster
11/1995
11/22/1995CN2213375Y Vacuum changeover switch
11/08/1995CN2212252Y Three phase magnetic saturation shunt circuit magnetic voltage regulator
11/08/1995CN2212251Y Vacuum loaded tapping switch for dry box type transformer
11/02/1995EP0680062A2 Tap changer
11/01/1995CN2211646Y Constant voltage regulator with dual compensation
10/1995
10/18/1995CN2210456Y Transformer for the test of resonance
10/18/1995CN2210455Y Division connection switch with non-exciting
10/12/1995DE4407945C1 Switching device for load change-over or load selection switch
09/1995
09/26/1995US5453685 Inductive position sensing device and apparatus with selectable winding configuration
09/20/1995CN2208268Y Electric reactor with stepless adjustable inductance
09/14/1995WO1995024724A1 Switching arrangement for load change-over switches of step switches and for selector switches
09/12/1995US5450052 Magnetically variable inductor for high power audio and radio frequency applications
09/08/1995WO1995024005A1 An electrically controllable inductor
08/1995
08/16/1995EP0667629A2 Transformer and A.C. arc welder
08/02/1995CN1106170A Equivalent balanced transformer
07/1995
07/26/1995CN1105774A Single pole sub-connecting switch with linear contact
07/26/1995CN1105773A Load selector used in stepping switch of adjustable transformer
07/11/1995US5432493 Two linear differential transformers with armature
06/1995
06/29/1995WO1995017757A1 Series circuit transformer
06/28/1995EP0660511A2 Automatic gain control in radio receivers
06/21/1995CN2201716Y Vottage-regulating on-load tapping switch for transformer
06/20/1995US5426409 Current controlled variable inductor
05/1995
05/24/1995CN2198737Y Brightness regulator for daylight lamp
05/17/1995CN1028462C Transformer shunting switch with wearless contact
04/1995
04/26/1995EP0650173A1 A three-phase autotransformer with a balancing function
04/26/1995EP0649564A1 On-load tap changer.
04/26/1995CN1102009A Autoformer
04/11/1995US5406437 Zero phase sequence current filter with adjustable impedance
03/1995
03/22/1995EP0644562A1 Electrical changeover switching
03/22/1995CN2192946Y Dry hollow reactor for outdoor
03/08/1995EP0641482A1 Arrangement for generating the ignition voltage for thyristors.
03/08/1995CN2191470Y Excitation-free take-off switch
03/08/1995CN1099917A Iron lose resistant-changing method and device
03/07/1995US5396036 Roller contact device
03/01/1995EP0640241A1 Step switch.
02/1995
02/21/1995US5392018 Electronically tuned matching networks using adjustable inductance elements and resonant tank circuits
02/08/1995EP0637829A1 Tap changer for tapped transformer
02/08/1995CN2189348Y Three-phase transformer
02/02/1995WO1995003617A1 Planar transducer
02/01/1995EP0637122A1 An apparatus and method of controlling a step-down ratio of an autotransformer in response to an input voltage
02/01/1995CN2188800Y Two-winding contact voltage regulator
01/1995
01/17/1995US5382937 Coil device
01/04/1995CN2186952Y Non-exciting shunting switch
12/1994
12/28/1994CN2186435Y Load voltage regulating device of active bridge distribution transformer
12/20/1994US5374781 Contact assembly for selector of step transformer
12/15/1994DE4317533A1 Variable-ratio transformer
12/14/1994CN1096397A Load selector used for switch of adjustable transformer
12/06/1994US5371485 Two core phase angle regulating transformer
11/1994
11/29/1994US5369388 LTC compensating winding for parallel operation of transformers
11/23/1994CN2183635Y Reactance startor for multi-function electric motor
11/23/1994CN1026738C Non-linear inductor with magnetic field reduction
11/09/1994CN2182448Y Rolling contact for tapping switch of transformer
11/03/1994DE4326127C1 Stepping switch for a tapped transformer
10/1994
10/19/1994CN2180001Y Butterfly non-exciting tap switch
09/1994
09/27/1994US5350980 Nonlinear inductor with magnetic field reduction
09/07/1994EP0614201A1 Transformer arrangement
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