Patents by Inventor Mikitaka Tamai
Mikitaka Tamai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20030102842Abstract: The battery pack is provided with output terminals and an authenticity discriminating circuit. The authenticity discriminating circuit is not supplied power from the rechargeable battery, nor is it connected to either the rechargeable battery or the output terminals. The authenticity discriminating circuit is provided with a receiver section which receives an activating radio wave from the electrical equipment, a transmitter section which sends an authentication radio wave as a signal to discriminate authenticity when the receiver section receives the activating radio wave, and a power supply section which converts the activating radio wave to direct current to supply electrical power to the receiver section and the transmitter section.Type: ApplicationFiled: November 26, 2002Publication date: June 5, 2003Inventors: Mikitaka Tamai, Kazuhiro Toyoda
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Publication number: 20030003357Abstract: The battery pack has a battery, output terminals to bring out the battery electrodes, and a molding holder to connect to the battery as well as retain the output terminals. The battery pack is molded with at least the battery, the molding holder, and its connecting region inserted into a molded plastic resin region. The molded plastic resin region exposes output terminal surfaces, and also joins the battery, output terminals, and molding holder as a single unit.Type: ApplicationFiled: June 27, 2002Publication date: January 2, 2003Inventors: Mikitaka Tamai, Yasushi Inoue, Hiroki Teraoka
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Patent number: 6492058Abstract: The battery pack houses a protection circuit along with a rechargeable cell in a case. The protection circuit is provided with switching devices to control current flow in the rechargeable cell, and a control circuit to control the switching devices. The protection circuit is molded in a single package with insulating material to make a one-package unit. The one-package unit is retained in a holding space in an insulating holder. The one-package unit, insulating holder, and rechargeable cell are held in the case.Type: GrantFiled: February 24, 2000Date of Patent: December 10, 2002Assignee: Sanyo Electric Co., Ltd.Inventors: Atsushi Watanabe, Yasushi Inoue, Ryosuke Kubo, Keiji Ishihama, Yasuhiro Yamagami, Takuya Matsuda, Mikitaka Tamai
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Publication number: 20020140401Abstract: The battery pack has batteries, a printed circuit board with battery protection circuit components mounted on it, and a circuit breaker contained in a case. The circuit breaker switches off if excessive current flows in the batteries, or if battery temperature exceeds a specified temperature. The circuit breaker has a plurality of solder terminals attached to its casing, and one or a plurality of the solder terminals are attached to the printed circuit board by solder re-flow. The printed circuit board is connected to the batteries via leads and is disposed in a fixed position inside the case. The circuit breaker is mounted in a fixed position inside the case via the printed circuit board.Type: ApplicationFiled: March 27, 2002Publication date: October 3, 2002Inventors: Atsushi Watanabe, Mikitaka Tamai, Hiroki Teraoka
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Patent number: 6064184Abstract: A charging circuit is provided with a charge control switch connected in series with a rechargeable battery, and a current sensing circuit to determine whether or not current flows through the rechargeable battery. A charging control circuit is also included to determine a charge state of the rechargeable battery and to control operation of the charge control switch. Further an operation control circuit for allowing operation of the charging control circuit in response to current flow through the rechargeable battery determined by the current sensing circuit.Type: GrantFiled: January 25, 1999Date of Patent: May 16, 2000Assignee: Sanyo Electric Co., Ltd.Inventor: Mikitaka Tamai
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Patent number: 5898293Abstract: The method of preventing battery over-discharge measures battery voltage with a control circuit, and switches an over-discharge protection switch connected in series with the batteries off with the control circuit when battery voltage drops below a minimum set voltage. Once the over-discharge protection switch turns to an off state, the off voltage at the output side of the switch is measured, and the over-discharge protection switch is held in the off state by this off voltage. When battery voltage rises above the minimum set voltage, return of the over-discharge protection switch to the on state is prevented.Type: GrantFiled: July 22, 1997Date of Patent: April 27, 1999Assignee: Sanyo Electric Co., Ltd.Inventors: Mikitaka Tamai, Kouji Negoro
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Patent number: 5828202Abstract: The battery apparatus has a circuit to turn off a switching device and suspend charging when rechargeable battery voltage exceeds a specified voltage, and to turn on the switching device and resume charging when rechargeable battery voltage drops below the specified voltage. The switching device is switched on and off to pulse charge the rechargeable battery. When cut-off of charging voltage to the rechargeable battery is detected, an over-ride circuit forces the switching device on, or a forced discharge circuit discharges the rechargeable battery until battery voltage drops below the specified voltage.Type: GrantFiled: February 27, 1997Date of Patent: October 27, 1998Assignee: Sanyo Electric Co., Ltd.Inventor: Mikitaka Tamai
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Patent number: 5764033Abstract: The rechargeable battery protection circuit of this invention is provided with a switching system connected in series with the rechargeable battery, a current detection system to measure charging current flowing through the rechargeable battery, and a control system to control the switching system on and off depending on measurement results from the current detection system. The control system puts the switching system in the off state when charging current greater than a specified value flows through the rechargeable battery. This prevents rechargeable battery charging with excessive current.Type: GrantFiled: March 24, 1997Date of Patent: June 9, 1998Assignee: Sanyo Electric Co., Ltd.Inventor: Mikitaka Tamai
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Patent number: 5747969Abstract: The charging method repeatedly charges and suspends charging to pulse charge a rechargeable battery. Charging is suspended only after a given amount of charge is transferred to the battery. Battery voltage is measured during the period of suspended charging, and charging is resumed only after the voltage of the battery drops below a first prescribed voltage. This situation is continuously repeated to pulse charge a rechargeable battery.Type: GrantFiled: November 13, 1996Date of Patent: May 5, 1998Assignee: Sanyo Electric Co., Ltd.Inventor: Mikitaka Tamai
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Patent number: 5705911Abstract: An over-charge protection FET and an over-discharge protection FET are connected in series with the rechargeable battery and turned ON or OFF by a control circuit. An ON-OFF switching device is connected between G and S of the over-charge protection FET and controlled by an output signal from the control circuit. An over-charge protection FET drain voltage input circuit is connected to the input side of the ON-OFF switching device. When the drain voltage of the over-charge protection FET is high, the input circuit sets the ON-OFF switching device to the ON state to forcibly set the over-charge protection FET to the OFF state.Type: GrantFiled: November 27, 1996Date of Patent: January 6, 1998Assignee: Sanyo Electric Co., Ltd.Inventor: Mikitaka Tamai
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Patent number: 5640080Abstract: A charging apparatus charges a secondary battery in alternating charging and rest periods. The charge amount supplied in the charging periods is restricted to an amount which reduces or eliminates deterioration of the secondary battery by overcharging.Type: GrantFiled: July 6, 1995Date of Patent: June 17, 1997Assignee: Sanyo Electric Co., Ltd.Inventors: Mikitaka Tamai, Tooru Amazutsumi
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Patent number: 5637979Abstract: A plurality of series connected rechargeable batteries are charged by detecting battery voltages and controlling charging current. Normal charging is performed until any one battery voltage reaches a prescribed voltage. After any one battery voltage reaches the prescribed voltage, all batteries are charged such that a charging current is controlled to keep each battery voltage from exceeding the prescribed voltage.Type: GrantFiled: January 18, 1996Date of Patent: June 10, 1997Assignee: Sanyo Electric Co., Ltd.Inventors: Mikitaka Tamai, Takaharu Ohira
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Patent number: 5606240Abstract: A battery charger has a battery capacity detector for detecting the remaining battery capacity and a timer setter for controlling the timer setting that determines the battery charging time based on the results from the battery capacity detector. The battery capacity detector measures the battery voltage, the battery constant current charging time, or the battery capacity. The timer includes a protection timer to forcibly end battery charging and a constant current charging timer to establish the constant current charging interval.Type: GrantFiled: September 19, 1995Date of Patent: February 25, 1997Assignee: Sanyo Electric Co., Ltd.Inventors: Toshiharu Kokuga, Mikitaka Tamai, Tetsuya Okada
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Patent number: 5585994Abstract: A first series circuit of a current detector and a first switch is connected in series with a battery, and a second series circuit of a resistor and a second switch is connected in parallel with the first series circuit. A control device controls an on and off state of the first and second switches to provide over-current protection of the battery. In particular, the control device turns off the first switch to cut-off battery over-current and turns on the second switch when the battery current exceeds a specified level as detected by the current detector. Then, after the battery current, which flows through the second series current, drops below the specified level, the first switch is returned to an on state to again allow battery discharge.Type: GrantFiled: January 13, 1994Date of Patent: December 17, 1996Assignee: Sanyo Electric Co., Ltd.Inventors: Mikitaka Tamai, Takaharu Ohira, Tetsuya Okada
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Patent number: 5557192Abstract: The charging time for rechargeable batteries which require constant voltage charging is reduced by compensating for IR losses in the battery pack circuitry. A voltage detection circuit measures battery pack terminal voltage and a charging control circuit insures that battery voltage does not exceed a reference voltage. The system is improved by a compensation circuit which at least compensates for resistance in circuitry other than the rechargeable battery.Type: GrantFiled: August 12, 1994Date of Patent: September 17, 1996Assignee: Sanyo Electric Co., Ltd.Inventor: Mikitaka Tamai
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Patent number: 5477124Abstract: A circuit effectively prevents excessive discharge of a rechargeable battery that is either detachable from, or internal to an electrical apparatus. The circuit has a battery voltage detector, a comparitor to compare the battery voltage with a reference voltage, and a controller to cut-off power drain from a discharged battery when its voltage drops below the reference voltage. The discharged battery is electrically cut-off from both the load and the comparitor.Type: GrantFiled: August 4, 1994Date of Patent: December 19, 1995Assignee: Sanyo Electric Co., Ltd.Inventor: Mikitaka Tamai
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Patent number: 5477130Abstract: Connection between internal batteries and external terminals of the battery pack is controlled by semiconductor switching devices, rather than by switches with mechanical contacts. When the battery pack Is not connected, battery short circuits are prevented by non-conduction of the switching devices. When the battery pack is attached to electrical equipment, a control circuit turns the switching devices on to supply power to the equipment. If the electrical equipment is a battery charger, the switching devices are turned on to supply power to the battery pack.Type: GrantFiled: June 14, 1994Date of Patent: December 19, 1995Assignee: Sanyo Electric Co., Ltd.Inventors: Hisashi Hashimoto, Mikitaka Tamai
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Patent number: 5442274Abstract: A hysteresis battery charging method repeats peak and trough voltage and current waveforms taking the battery to a temporary over-voltage state during peak charging. This method achieves rapid recharge while avoiding battery performance degradation. Constant current charging or quasi-constant current charging is performed during peak charging. During troughs, charging is either suspended or reduced from that during peak charging. After battery capacity has reached a set value by hysteresis charging, an optimum voltage is maintained by constant voltage charging.Type: GrantFiled: August 26, 1993Date of Patent: August 15, 1995Assignee: Sanyo Electric Company, Ltd.Inventor: Mikitaka Tamai
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Patent number: 5397974Abstract: A first switch element is connected in series with a rechargeable battery, a second switch element is connected in parallel to the series circuit of the rechargeable battery and the first switch element, and a control circuit controls ON and OFF states of the first switch element and the second switch element. The control circuit is so constructed as to turn OFF the first switch element to stop discharging and at the same time turn ON the second switch element when the battery voltage becomes lower than a predetermined value. The second switch element maintains the first switch element in OFF state even when the battery voltage of the rechargeable battery rises by self resetting of the rechargeable battery. When a charging voltage is applied to the rechargeable battery, the control circuit then turns ON the first switch element and turns OFF the second switch element.Type: GrantFiled: January 18, 1994Date of Patent: March 14, 1995Assignee: Sanyo Electric Co., Ltd.Inventors: Mikitaka Tamai, Takaharu Ohira, Tetsuya Okada