Patents for H01F 30 - Fixed transformers not covered by group (4,595)
07/1991
07/17/1991EP0436969A1 High frequency thermode driver employing one-turn-secondary transformers
07/17/1991EP0436665A1 Variable speed, constant frequency generating system with input transformer
07/12/1991CA2023319A1 High frequency thermode driver employing one-turn-secondary transformers
07/11/1991WO1991010245A1 Transformer with voltage balancing tertiary winding
07/11/1991WO1991010244A1 Toric-type transformer
07/10/1991EP0436434A1 Toroidal transformer
07/09/1991US5030813 Welding apparatus and transformer therefor
06/1991
06/25/1991US5027099 Sensitive fault detection system for parallel coil air core reactors
06/18/1991US5025241 Transformer of ferrite closed magnetic circuit type
06/12/1991EP0431322A1 Ignition coil
06/11/1991US5023768 High voltage high power DC power supply
05/1991
05/29/1991EP0429315A2 High voltage high power DC power supply
05/25/1991CA2030582A1 High voltage high power dc power supply
05/23/1991DE3938577A1 Permanent magnet transformer generating electrical pulses - uses four-limbed yoke including magnet for three sec. windings
05/15/1991EP0302856B1 Improvements in ferroresonant constant-voltage transformers
05/08/1991EP0425574A1 Transformer having symmetrical push-pull windings
05/07/1991CA1283944C Continuous transformer and motor
03/1991
03/26/1991US5003277 Phase-shifting transformer with a six-phase core
03/26/1991CA1282010C Inductive coupled power system
02/1991
02/06/1991EP0411171A1 Own demand supply for a medium voltage switchgear device
01/1991
01/21/1991WO1991001040A1 Three-phase transformer
01/16/1991CN1048626A Shunt reactor common type transformer
01/09/1991EP0406555A1 Shared shunt reactor type transformer
01/08/1991US4983859 Magnetic device for high-voltage pulse generating apparatuses
12/1990
12/18/1990US4978906 Picture frame matrix transformer
12/12/1990EP0370102A4 High frequency matrix transformer
12/04/1990US4975822 Harmonic reduction for multi-bridge converters
12/04/1990US4975670 Air cooled transformer
11/1990
11/27/1990US4973930 Twin coil
11/27/1990CA1276974C Welding transformer and rectifier assembly
11/22/1990EP0398176A2 Harmonic reduction for multi bridge converters
11/08/1990DE3913558A1 Transformer with ferrite windings - has core with primary and secondary coils arranged on common sections in alternate manner
10/1990
10/23/1990US4965712 Transformer having plural-turn core
10/09/1990US4962362 Multi-magnetic field plural core transformer
10/03/1990EP0390643A1 Transformer of the closed ferrite magnetic circuit type
09/1990
09/25/1990CA1274588A1 Face connected instrument transformer
09/18/1990USRE33345 Toroid transformers and secondary windings
09/12/1990CN1009596B Method and arrangement for controlling the magnetizing current passing through a transformer
07/1990
07/24/1990US4943763 Ferroresonant transformer with dual outputs
06/1990
06/26/1990US4937730 Constant voltage power supply
06/26/1990US4937729 Chopper power supply including a printed circuit transformer
06/13/1990DE3841412A1 Transformer, especially power transformer
06/12/1990US4933830 Switching power supply
06/05/1990US4931761 Compact transformer
05/1990
05/30/1990EP0370102A1 High frequency matrix transformer
05/29/1990US4930059 Switched-mode DC-to-DC power converter
05/22/1990US4928020 Saturable inductor and transformer structures for magnetic pulse compression
05/17/1990WO1990005406A1 Variable speed, constant frequency generating system with input transformer
05/01/1990US4922405 High voltage transformer
04/1990
04/25/1990EP0365407A1 Power transformer with reduced heat generation
04/24/1990CA1268219A1 Ac power supply with improved cooling means
04/10/1990US4916425 Electromagnetic device
03/1990
03/27/1990US4912618 Variable speed, constant frequency generating system with input transformer
03/14/1990CN1040456A Transformer for compensating phase
03/13/1990US4908753 High-tension power supply for an image recorder
03/06/1990US4906960 Distribution transformer with coiled magnetic circuit
03/06/1990US4906859 Power supply circuit with symmetrically tapped auto-transformer
03/06/1990CA1266516A1 A.c. "and" gate
03/06/1990CA1266505A1 D.c. to d.c. converter
03/01/1990DE3928223A1 Magnetic device for HV pulse generator
02/1990
02/21/1990EP0355023A1 Phase-shifting transformer with a six-phase core
02/13/1990US4901048 Magnetic core multiple tap or windings devices
02/08/1990WO1990001232A1 Transformer having symmetrical push-pull windings
01/1990
01/31/1990EP0352969A2 Plank and frame transformer
01/31/1990EP0352924A2 Inductive device
01/30/1990US4897626 Cooling electromagnetic devices
01/30/1990US4896839 Apparatus and method for winding a strip of material into an arcuate elongate passage
01/24/1990EP0351583A1 Twin coil
01/17/1990EP0350767A1 Audio winding bridging an air gap
01/17/1990EP0350520A1 Noise filter and method of making the same
01/17/1990CN1006501B Inductance adjustment for transformers
01/09/1990US4893069 Ferroresonant three-phase constant AC voltage transformer arrangement with compensation for unbalanced loads
12/1989
12/27/1989EP0348316A1 Device with an electric, annular, insulated coil
12/21/1989DE3919569A1 Transformer
12/21/1989DE3918187A1 Iron core for electromagnetic appliances
12/12/1989US4887061 Transformer for a flyback type converter
11/1989
11/29/1989EP0343886A2 Circuit arrangements
11/21/1989CA1263159A1 Oscillating flux transformer
11/21/1989CA1263158A1 Rotating flux transformer
11/21/1989CA1263157A1 Rotating flux transformer
11/08/1989EP0340800A1 Moving magnetic field electric power converter
11/02/1989WO1989010654A1 High frequency matrix transformer
11/02/1989EP0339827A1 Flat voltage transformer
10/1989
10/24/1989US4875277 Formed metal core blocking method
10/19/1989WO1989009994A1 Saturable inductor and transformer structures for magnetic pulse compression
10/11/1989CN1036289A Modular high frequency power transformer
10/04/1989EP0335142A1 Transformer for switching network
10/04/1989CN1036102A Small transformer
09/1989
09/26/1989US4870558 Moving magnetic field electric power converter
09/26/1989CA1260088A1 High-power pulse transformer for short high-voltage and/or high-current pulses
09/19/1989US4868533 Transformer with a one-piece primary winding and housing
09/19/1989US4868532 Transformer with a two-piece primary winding and housing
09/12/1989US4866407 Noise filter and method of making the same
09/06/1989EP0330658A1 Heat convertor for an x ray generator
09/05/1989US4864486 Plank and frame transformer
08/1989
08/29/1989US4862129 Single-turn primary and single-turn secondary flat voltage transformer
08/22/1989US4860187 Magnetic flux coupled voltage multiplication apparatus
08/15/1989US4857878 Modular high frequency power transformer
08/01/1989US4853664 Three-phase transformer for cycloconverter
07/1989
07/27/1989WO1989006860A1 Transformer
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