Sony Corporation

Narumi China Corporation

Nippon Motorola, Ltd.

Kanji Murano

Susumu Nishigaki

Akira Sanpei

Yasuhito Eguchi

Takehisa Ishida

Tetsuo Sekiya

Yoshihisa Watanabe

Akihiko Ohashi

Hiroshi Kato

Shinsuke Yano

Masayuki Sato

Hitoshi Okada

Toshio Narushima

Senri Miyaoka

Masami Himuro

Tohru Fuwa

Kouichi Tatsuki

Hajime Tamiya

Circuit for preventing overcharge and overdischarge of secondary batteries is disclosed. Overcharge detecting comparators COMP2 and COMP4 each having a hysteresis circuit 1 are connected between positive and negative electrodes of series-connected secondary batteries Abat and Bbat, and overdischarge detecting comparators COMP1 and COMP3 each having a hysteresis circuit 2 are connected also between the above electrodes. Transistors T1, T2 and a resistor R are connected between the batteries for overflow of overcharge and balance of overdischarge. Upon detection of any overcharge by the comparator COMP2 or COMP4, the charge current is interrupted by a transistor T6, and simultaneously the overcharge overflow is discharged by the hysteresis circuit until the battery voltage is lowered to the hysteresis voltage. And after the discharge, the transistor T6 is turned on to resume recharging the batteries. Meanwhile, upon detection of any overdischarge by the comparator COMP1 or COMP3, the discharge current is interrupted by a transistor T5. Thus the overcharge and the overdischarge can be balanced by the hysteresis circuits 1 and 2 respectively.

Circuit for preventing overcharge and overdischarge of secondary

A battery protection circuit has a condition detecting circuit which detects a voltage across a secondary cell or cells and compares the detected voltage with a reference voltage to detect an overdischarged condition or an overcharged condition of the secondary cell or cells. A control unit controls a first switching element for cutting off a discharging current and a second switching element for cutting off a charging current based on a detected condition of the secondary cell or cells. A third switch element cuts off electric power supplied to the condition detecting circuit. The third switch element is rendered nonconductive when the overdischarged condition is detected by the condition detecting circuit.

Battery protection circuit

Circuit groups for preventing a battery from being deteriorated in efficiency due to a charging and discharging of each of secondary batteries is incorporated in a battery protection circuit for protecting a plurality of batteries connected in series to thereby extend a life of the battery. The battery protection circuit incorporates therein power down means for extending a time in which a voltage of a remaining capacity becomes 0V as much as possible by causing a current to flow only in the minimum circuit when the battery is overdischarged. Also, when a trouble such as a momentary overcurrent or the like is detected, the circuit can be prevented from set in the power down mode.

Battery charge control circuit

An overcharge preventing device and an overdischarge preventing device for a nonaqueous electrolyte secondary battery having voltage detectors and are provided to respectively detect terminal voltages of batteries connected in series. A switch is provided in series to the batteries between a common terminal and a charge terminal. When the terminal voltage of at least one of the batteries exceeds a battery design voltage in charging the batteries, the switch is turned off in response to an output from the corresponding voltage detectors, thereby cutting off a charging current. Further, a voltage detector is provided to detect a terminal voltage of the series connected batteries. A switch is provided in series to the batteries between the common terminal and a discharge terminal. When the terminal voltage of the batteries becomes equal to or less than a set voltage in discharging the batteries, the switch is turned off in response to an output from the voltage detector, thereby cutting off a discharging current.

Overcharge preventing device and overdischarge preventing device for a

Described herein is a rotational bearing system incorporating a ball bearing to support a shaft or housing in freely rotatable state through rolling contact with the ball bearing, the rotational bearing system comprising: vibratory elements adapted to excite in resonant vibration a fixed shaft or a fixed housing in rolling contact with the ball bearings thereby to lower the frictional resistance of the ball bearing.

Bearing system

A rotational bearing system incorporates a ball bearing to support a freely rotatable shaft or housing through rolling contact with the ball bearing, the rotational bearing system comprises: vibratory elements adapted to excite in resonant vibration a fixed shaft or a fixed housing in rolling contact with the ball bearings to lower the frictional resistance of the ball bearing.

A novel electron beam addressible recording device is disclosed, in which a recording layer formed of ferroelectric material having secondary electron emissivity .delta. greater than 1 is provided in a vacuum chamber. One surface of the recording layer is applied with a predetermined potential and the other surface is caused to have different potentials from the predetermined potential by scanning it with an electron beam. The difference of the potentials between two surfaces of the recording layer, causes poling patterns corresponding to the data recorded to be formed. The recorded data in the form of poling direction can be detected by electron beam scanning.

Electron beam addressible recording device utilizing ferroelectric

There is provided a dielectric porcelain used as dielectric resonator mainly in a microwave range. According to the present invention, 0.1 to 5.3 mol % of one or more of Tb.sub.4 O.sub.7, CeO.sub.2, TeO.sub.2, Gd.sub.2 O.sub.3 and Dy.sub.2 O.sub.3 as additive is admixed to a dielectric material Pb.sub.x Zr.sub.(1-x) O.sub.(2-x) wherein 0.42.ltoreq..ltoreq.0.69 to procure a dielectric constant while keeping the dielectric loss to a lower value and simultaneously controlling temperature characteristics of the dielectric constant, that is, temperature characteristics of the resonant frequency.

Dielectric porcelain

A dielectric ceramic composition for microwave applications having the formula ##EQU1## wherein x, y and z are molar percentages and 10.ltoreq.x.ltoreq.22, 58.ltoreq.y.ltoreq.80 and 8.ltoreq.z.ltoreq.22, O&lt;n.ltoreq.25, and x+y+z=100;

Dielectric ceramic composition for microwave application

An electro-optic light shutter is disclosed which includes a ceramic body having electro-optic effect and a pair of electrodes applying A.C. voltage to the ceramic body to cause electro-optic effect, wherein the ceramic body is formed of PLZT ceramics having memory effect at a room temperature and loses the memory effect at an elevated operating temperature caused by application of A.C. voltage to the ceramic body.

Electro-optic light shutter

An electro-mechanical transducer having a first layer made of piezoelectric material having opposing major surfaces, a pair of electrodes formed on the major surfaces of the first layer, respectively, and a second layer clamped at its one surface to one of the surfaces of the first layer. In this case, the first layer has a Young's modulus of E, the second layer has a Young's modulus Ex in one direction and a Young's modulus Ey in the direction perpendicular to the one direction in the major surface, the Young's moduli E, Ex, Ey satisfy the relation E&gt;Ey, Ex&gt;Ey, and one end of the first and second layers along the one direction is clamped. The thickness of the electrode is selected between 0.1 and 3 .mu.m to obtain large amount of displacement at the other end. The outer surface of the electrode may be coated with a conductive paste to ensure voltage supply to the whole surface of the electrode.

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Tokyo, Japan

Kanji Murano