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41. 发明专利

JPH11339365A HARD DISK DRIVER DRIVING CIRCUIT 失效
公开(公告)号：JPH11339365A
公开(公告)日：1999-12-10
申请号：JP14264098
申请日：1998-05-25
申请人： HITACHI LTD , HITACHI ULSI SYS CO LTD
发明人： SATO HIROSHI , SEKI KUNIO , MOCHIZUKI HIROTAKA , KUROSAWA YOSHIHISA
IPC分类号： G11B19/00 , G11B21/02
摘要： PROBLEM TO BE SOLVED: To eliminate the dependency on the boosting circuit, which makes the constitution of the hard disk driver complex and becomes the noise generating source, to effectively suppress the generation of the power source line noise caused by the counter electromotive force of a spindle motor during a power supply interruption and to surely conduct a retract operation employing the force. SOLUTION: A head retracting movement is conducted by giving the counter electromotive force, that is generated by the inertial rotation of a spindle motor 4 when the power supply is interrupted. The output stage of a spindle driving circuit is constituted of MOS transistors M1 and M2. The parasitic diodes formed between the back gates BG of the transistors M1 and M2 and the sources and/or the drains are used to prevent the reverse current, that is caused by the counter electromotive force, to flow back toward a power supply line.

42. 发明专利

JPH09214261A POWER AMPLIFIER CIRCUIT 失效
公开(公告)号：JPH09214261A
公开(公告)日：1997-08-15
申请号：JP1654996
申请日：1996-02-01
申请人： HITACHI LTD , HITACHI TOBU SEMICONDUCTOR LTD
发明人： MAEDA MASATOSHI , SEKI KUNIO , TAKESHITA RITSUJI
IPC分类号： H03F3/30 , H04B1/10
摘要： PROBLEM TO BE SOLVED: To provide the power amplifier circuit increasing a maximum output power while avoiding adverse effect on other circuit such as a tuner. SOLUTION: In the power amplifier circuit having a push-pull output circuit, NPN TRs are employed for output transistors (TRs) Q2, Q5 for a push-side 1 and a pull-side 2 of the push-pull output circuit and the power amplifier circuit is provided with a boosting circuit boosting a power supply voltage and a changeover means SWO applying selectively a voltage generated in the boosting circuit 3 or the usual power supply voltage to a pre-stage circuit supplying a base current of the push-side output TR Q2. The changeover means SWO is switched by a mode control signal or the like.

43. 发明专利

JPH08168282A MOTOR DEVICE 失效
公开(公告)号：JPH08168282A
公开(公告)日：1996-06-25
申请号：JP30515994
申请日：1994-12-08
申请人： HITACHI LTD , HITACHI TOBU SEMICONDUCTOR LTD
发明人： SEKI KUNIO , TSUNODA TOSHIYUKI , KIMURA REIICHI , OKUBO YUICHI
IPC分类号： H02P29/00 , H02P5/00
摘要： PURPOSE: To rationalize the assembling of a motor device by generating an index pulse whenever the motor passes through a specific angular position and variably setting the generating timing of the index pulse by delaying the timing within an electrically programmable range. CONSTITUTION: Whenever a motor 1 passes through a specific angular position, a Hall element (Hi) outputs a detecting signal. When the detecting signal is outputted, an index pulse (Pi) having a pulse width tw which is decided by the current value of a constant-current source 10 and capacitance value of a capacitance element C2 is generated with a time lag td which is decided by the resistance value of a fixed resistor Rt0, capacitance value of a capacitance element C1, reference voltages V1 and Vth1 and outputted from a collector Q3. The generating timing of the pulse (Pi) is corrected by means of an external delaying element composed of the resistor RtO and element C1 and a delaying element 34 while the timing fluctuates due to the fitting error of the element (Hi), etc. Namely, the timing can be corrected by using the time lag td which is variably set in accordance with an externally executed electrical program through terminals A and B.

44. 发明专利

JPH0624300B2 失效
公开(公告)号：JPH0624300B2
公开(公告)日：1994-03-30
申请号：JP21684282
申请日：1982-12-13
申请人： HITACHI LTD
发明人： SEKI KUNIO , TAKESHITA RITSUJI , HORIUCHI KENJI
IPC分类号： H03F1/32 , H03F1/42 , H03F1/52 , H03F3/30 , H03G11/00

45. 发明专利

JPH05315935A INPUT CIRCUIT 失效
公开(公告)号：JPH05315935A
公开(公告)日：1993-11-26
申请号：JP12087692
申请日：1992-05-13
申请人： HITACHI LTD
发明人： SEKI KUNIO , OKUBO YUICHI
IPC分类号： H03K19/0175
摘要： PURPOSE:To variably set up the logical threshold of an input circuit over a wide range without changing internal configuration by connecting a resistor between an external logical signal source and an input terminal in series. CONSTITUTION:When a current 11 flowing from an input terminal Pin exceeds a certain threshold current Ith determined by voltage impressed between the bases and emitters of transistors(TRs) Q1 to Q4 and the values of resistors R2 to R5, a logical signal Vcnt applied to an internal circuit 4 is switched from a high level to a low level. When the current 11 obtained in the low state of an output Vs from a logical signal source 1 is allowed to surely exceed the threshold current Ith, the circuit 4 can be logically driven by the output Vs of the signal source 1. The current 11 in the low state of the output Vs can be optionally changed by the resistance value of a resistor Rx connected to the input terminal Pin in series.

46. 发明专利

JPH0590944A INPUT CIRCUIT 失效
公开(公告)号：JPH0590944A
公开(公告)日：1993-04-09
申请号：JP27684191
申请日：1991-09-27
申请人： HITACHI LTD
发明人： SEKI KUNIO , OKUBO YUICHI
IPC分类号： H03K19/0175 , H03K19/018
摘要： PURPOSE:To vary a logical threshold level of the input circuit over a wide range by converting a current flowing through an externally mounted resistor between an external logical signal source and an input terminal into a voltage to apply on/off control to a switching element. CONSTITUTION:An external logical signal source 1 is connected to an input terminal Pin via an externally mounted resistor Rx. A current voltage conversion circuit 32 converting a current 11 flowing from the input terminal Pin externally through the externally mounted resistor Rx into a voltage V1 is made up of pnp bipolar transistors (TRs) Q2, Q3 and resistors R2-R4, and the transferred current I1 is converted into the voltage V1 at a conversion ratio set by resistors R3, R4 connecting to a collector of the pnp bipolar TR Q3. Then the npn bipolar TR Q4 acts like a switching element subject to on/off control by the conversion voltage VI and an internal circuit 4 is logically driven by the on/off operation.

47. 发明专利

JPH0429027B2 失效
公开(公告)号：JPH0429027B2
公开(公告)日：1992-05-15
申请号：JP18198780
申请日：1980-12-24
申请人： HITACHI LTD
发明人： SEKI KUNIO
IPC分类号： G01R19/145 , G01R19/00 , G01R19/15 , G01R19/155 , G01R19/165 , G01R19/32

48. 发明专利

JPH0331004B2 失效
公开(公告)号：JPH0331004B2
公开(公告)日：1991-05-02
申请号：JP7921481
申请日：1981-05-27
申请人： HITACHI LTD
发明人： TAKESHITA RITSUJI , SEKI KUNIO
IPC分类号： H03F3/20

49. 发明专利

JPH0119286B2 失效
公开(公告)号：JPH0119286B2
公开(公告)日：1989-04-11
申请号：JP1430781
申请日：1981-02-04
申请人： HITACHI LTD
发明人： SEKI KUNIO
IPC分类号： H03F1/52 , H03F1/42 , H03F3/20 , H03F3/30 , H03G11/00 , H03G11/02

50. 发明专利

JPS641323A SWITCHING REGULATOR 失效
公开(公告)号：JPS641323A
公开(公告)日：1989-01-05
申请号：JP15545987
申请日：1987-06-24
申请人： HITACHI LTD
发明人： SEKI KUNIO
IPC分类号： H03K17/06
摘要： PURPOSE:To improve the degree of integration of a switching regulator, by using an n-channel MOS transistor as a switching transistor and respectively applying a supply voltage obtained from one power supply circuit and a bootstrap voltage boosted by means of a bootstrap circuit to the drain and gate of the transistor respectively. CONSTITUTION:A pulse-like control signal is supplied to an n-channel MOS transistor M1 and, at the same time, a supply voltage obtained from one power source is applied across the drain of the transistor M1. Then a voltage boosted by means of a bootstrap circuit 2 is applied to the gate of the transistor M1 so as to make the gate voltage higher than the drain voltage. Therefore, the n-channel MOS transistor M1 can be allowed to execute switching operations by means of one power source. Accordingly, the degree of integration can be improved when this regulator is constituted of an IC and, in addition, a simple power supply circuit can be used.

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