Inventor · disambiguated record
Norikazu Tokunaga
Also filed as: TOKUNAGA NORIKAZU
32 granted patents·3 pending applications·1,924 citations·filing 1976–2004
98Inventor score
Top patents by PatentIndex Score
35 records- 0198US4692643ASemiconductor switching device having plural MOSFET's, GTO's or the like connected in seriesHITACHI LTD·Filed 1984·Granted Sep 8, 1987·114 cites·26 claims
- 0296US5297015APower supply control systemHITACHI LTD·Filed 1990·Granted Mar 22, 1994·170 cites·27 claims
- 0395US6795322B2Power supply with uninterruptible functionHITACHI LTD·Filed 1999·Granted Sep 21, 2004·369 cites·23 claims
- 0494US6297616B1Charge and discharge system for electric power storage equipmentHITACHI LTD·Filed 2000·Granted Oct 2, 2001·132 cites·13 claims
- 0593US5446645AInverter apparatus and uinterruptible power supply using the sameHITACHI LTD·Filed 1993·Granted Aug 29, 1995·279 cites·4 claims
- 0691US5210479ADrive circuit for an insulated gate transistor having overcurrent detecting and adjusting circuitsHITACHI LTD·Filed 1989·Granted May 11, 1993·58 cites·27 claims
- 0789US6489756B2DC-DC converter with switchable control modeHITACHI LTD·Filed 2001·Granted Dec 3, 2002·63 cites·14 claims
- 0888US6580597B2Voltage regulator module for micro processor and CPO using a super capacitorHITACHI LTD·Filed 2002·Granted Jun 17, 2003·48 cites·12 claims
- 0987US6381152B1Method of driving semiconductor switching device in non-saturated state and power supply apparatus containing such a switching deviceHITACHI LTD·Filed 2000·Granted Apr 30, 2002·32 cites·17 claims
- 1087US4777575ASwitching power supplyHITACHI LTD·Filed 1987·Granted Oct 11, 1988·56 cites·29 claims
- 1185US6567261B2DC-DC step-down converter with super capacitorHITACHI LTD·Filed 2002·Granted May 20, 2003·37 cites·6 claims
- 1284US7157810B2Backup power supplyHITACHI COMP PERIPHERALS CO·Filed 2004·Granted Jan 2, 2007·47 cites·15 claims
- 1383US7053502B2Power supply with uninterruptible functionHITACHI COMP PERIPHERALS CO·Filed 2004·Granted May 30, 2006·55 cites·10 claims
- 1483US6977448B2Backup power supplyHITACHI COMP PERIPHERALS CO·Filed 2003·Granted Dec 20, 2005·46 cites·11 claims
- 1583US6507507B2DC power supply deviceHITACHI LTD·Filed 2001·Granted Jan 14, 2003·41 cites·11 claims
- 1679US6643152B2DC power supply deviceHITACHI LTD·Filed 2002·Granted Nov 4, 2003·26 cites·9 claims
- 1777US4933830ASwitching power supplyHITACHI LTD·Filed 1989·Granted Jun 12, 1990·31 cites·10 claims
- 1876US6496395B2Direct-current power-supply apparatus, control circuit thereof and semiconductor integrated circuit device for power supplyHITACHI LTD·Filed 2001·Granted Dec 17, 2002·28 cites·16 claims
- 1976US5285365APower conversion system, method for controlling the same, and uninterruptible power supply using the sameHITACHI LTD·Filed 1991·Granted Feb 8, 1994·49 cites·15 claims
- 2073US5115386ACircuit for controlling an electric power supply apparatus, a method therefor and an uninterruptible power supplyHITACHI LTD·Filed 1990·Granted May 19, 1992·48 cites·20 claims
- 2171US4866589AVoltage resonance type switching power source apparatusHITACHI LTD·Filed 1988·Granted Sep 12, 1989·28 cites·24 claims
- 2268US6603671B2Synchronized rectifier voltage step down DC-DC converter and control circuit thereforHITACHI LTD·Filed 2001·Granted Aug 5, 2003·22 cites·22 claims
- 2365US4878163APulse width modulated inverter with high-to-low frequency output converterHITACHI LTD·Filed 1988·Granted Oct 31, 1989·23 cites·6 claims
- 2464US5262935AParallel inverter control apparatusHITACHI LTD·Filed 1991·Granted Nov 16, 1993·41 cites·13 claims
- 2562US5274541AParallel circuit module including a diode and an IGBTHITACHI LTD·Filed 1990·Granted Dec 28, 1993·32 cites·1 claims
- 2655US6738270B2Parallel power source systemRENESAS TECH CORP·Filed 2001·Granted May 18, 2004·13 cites·5 claims
- 2751US4292550AGate control circuit with capacitor for field controlled thyristorHITACHI LTD·Filed 1979·Granted Sep 29, 1981·8 cites·7 claims
- 2842US4855887ACurrent and frequency converter having means to reduce switching lossesHITACHI LTD·Filed 1988·Granted Aug 8, 1989·8 cites·9 claims
- 2940US2003197494A1DC-DC converter and a method of controlling thereofHITACHI LTD·Filed 2003·Application pending·0 cites
- 3040US2002186576A1Backup power supplyFiled 2002·Application pending·0 cites
- 3138US4122516AInverter control apparatusHITACHI LTD·Filed 1977·Granted Oct 24, 1978·7 cites·21 claims
- 3236US4306138APower supply apparatus for resistance welder including means for preventing polarized transformer excitationHITACHI LTD·Filed 1979·Granted Dec 15, 1981·4 cites·7 claims
- 3335US2002185994A1DC-DC converter and a method of controlling thereofHITACHI LTD·Filed 2002·Application pending·0 cites
- 3434US4737974AInverter type switching power supply with transformer and short circuit arrangement thereforHINO HIROFUMI·Filed 1985·Granted Apr 12, 1988·9 cites·9 claims
- 3527US4084222AHigh-voltage power supply deviceHITACHI LTD·Filed 1976·Granted Apr 11, 1978·0 cites·10 claims
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Identity basis: PatentsView inventor disambiguation (2025Q4-odp release). How scoring works →