Inventor

Norikazu Tokunaga

Inventor

Hitachi, JP

Overview

32→

Patents

1978–2007

Patent span

Electricity

Primary field (CPC H)

Patents· 32 as inventor

Public. Assignee & technology derived from the patent record. Each patent links to its LexDana page.

H02Mprimary

H02MApparatus for conversion between ac and ac, between ac and dc, or between dc and dc, and for use with mains or similar power supply systems39%

H02JElectric power networks17%

H03KPulse technique10%

Y02BClimate change mitigation technologies related to buildings, e.g. housing, house appliances or related end-user applications10%

H05BElectric heating5%

H10WGeneric packages, interconnections, connectors or other constructional details of devices covered by class h105%

B23KSoldering or unsoldering2%

B60LPropulsion of electrically-propelled vehicles2%

H01FMagnets2%

H01RElectrically-conductive connections2%

PatentTitleYear

7,157,810'Backup power supply'2007 7,053,502'Power supply with uninterruptible function'2006 6,977,448'Backup power supply'2005 6,795,322'Power supply with uninterruptible function'2004 6,738,270'Parallel power source system'2004 6,643,152'DC power supply device'2003 6,603,671'Synchronized rectifier voltage step down DC-DC converter and control circuit therefor'2003 6,580,597'Voltage regulator module for micro processor and CPO using a super capacitor'2003 6,567,261'DC-DC step-down converter with super capacitor'2003 6,507,507'DC power supply device'2003 6,496,395'Direct-current power-supply apparatus, control circuit thereof and semiconductor integrated circuit device for power supply'2002 6,489,756'DC-DC converter with switchable control mode'2002 6,381,152'Method of driving semiconductor switching device in non-saturated state and power supply apparatus containing such a switching device'2002 6,297,616'Charge and discharge system for electric power storage equipment'2001 5,446,645'Inverter apparatus and uinterruptible power supply using the same'1995 5,297,015'Power supply control system'1994 5,285,365'Power conversion system, method for controlling the same, and uninterruptible power supply using the same'1994 5,274,541'Parallel circuit module including a diode and an IGBT'1993 5,262,935'Parallel inverter control apparatus'1993 5,210,479'Drive circuit for an insulated gate transistor having overcurrent detecting and adjusting circuits'1993 5,115,386'Circuit for controlling an electric power supply apparatus, a method therefor and an uninterruptible power supply'1992 4,933,830'Switching power supply'1990 4,878,163'Pulse width modulated inverter with high-to-low frequency output converter'1989 4,866,589'Voltage resonance type switching power source apparatus'1989 4,855,887'Current and frequency converter having means to reduce switching losses'1989 4,777,575'Switching power supply'1988 4,737,974'Inverter type switching power supply with transformer and short circuit arrangement therefor'1988 4,692,643'Semiconductor switching device having plural MOSFET\'s, GTO\'s or the like connected in series'1987 4,306,138'Power supply apparatus for resistance welder including means for preventing polarized transformer excitation'1981 4,292,550'Gate control circuit with capacitor for field controlled thyristor'1981 4,122,516'Inverter control apparatus'1978 4,084,222'High-voltage power supply device'1978

Career & activity timeline

Assembled from patent assignee/location history and declaration credentials.

1978–2004Patents assigned to HITACHI LTD (27)· patent assignee history

1978–2007Based in Hitachi, JP· patent location history

1988–1989Patents assigned to HITACHI DEVICE ENG (2)· patent assignee history

1988Patents assigned to HINO HIROFUMI (1)· patent assignee history

2002–2003Patents assigned to HITACHI TOBU SEMICONDUCTOR LTD (4)· patent assignee history

2003–2007Patents assigned to HITACHI COMP PERIPHERALS CO (6)· patent assignee history

Inventor activity

Assignee and location history derived from the patent record.

Assignees

Assignee	Patents	Span
HITACHI LTD	27	1978–2004
HITACHI COMP PERIPHERALS CO	6	2003–2007
HITACHI TOBU SEMICONDUCTOR LTD	4	2002–2003
HITACHI DEVICE ENG	2	1988–1989
HINO HIROFUMI	1	1988

Locations

Location	Patents	Span
Hitachi, JP	32	1978–2007