专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

71. 发明专利

JPS61228780A AMPLIFIER CIRCUIT 失效
公开(公告)号：JPS61228780A
公开(公告)日：1986-10-11
申请号：JP6893085
申请日：1985-04-03
申请人： HITACHI LTD
发明人： SHIMOKAWA RYUSHI , UEDA SEIICHI , KAMATA YASUHARU , YAMASHITA KENKICHI , KATO KAZUO , SATO HIDEO
IPC分类号： H04N5/14 , G09G1/00 , G09G1/28 , H03F3/68 , H03G3/10 , H04N5/16
摘要： PURPOSE:To supply an input signal having AC component and to hold the DC level of an input side by obtaining DC voltage with detecting an output signal level and holding the DC level of the input side with feedbacking the DC voltage to the input side. CONSTITUTION:It is assumed that amplifier circuits 11-13 are constituted with the same circuit constitutions. At a buffer amplifier 21, amplifiers A and B are provided and the output signals from the amplifiers are selectively transferred to the latter stage by a switch circuit 22. A part of an output voltage V0 from an output circuit 26 is supplied to a variable resistor VR to obtain a feedback signal Vf. A comparison circuit 27a at a detecting circuit 27 obtains a pedestal level by comparing a reference voltage Vref2 with the feedback signal Vf. A control circuit 27 turns a switch 3 to an on state in the period when the pedestal level is obtained. A capacitor C2 holds the pedestal level out of the period of the pedestal level. The output voltage Vp of an amplifier 27b is the voltage corresponded with the pedestal and sets bias voltages of the amplifiers A and B at a prescribed voltage level through resistors Ra and Rb.

72. 发明专利

JPS61205012A BIAS CONTROL SYSTEM FOR VARIABLE GAIN AMPLIFIER CIRCUIT 失效
公开(公告)号：JPS61205012A
公开(公告)日：1986-09-11
申请号：JP4481685
申请日：1985-03-08
申请人： HITACHI LTD
发明人： YAMASHITA KENKICHI , NISHIMOTO SATORU , KATO KAZUO , KAMATA YASUHARU , DOKEN TOMOHIKO
IPC分类号： H03G3/02
摘要： PURPOSE:To perform the gain control and the bias control independently of each other and at the same time to secure the high frequency wide range characteristics, by providing a current adding circuit at the next stage of a variable gain circuit and amplifying the output signal of the current adding circuit to perform the bias control. CONSTITUTION:The signal given from a waveform signal source 1 is supplied to a variable gain circuit 2 to undergo the gain control through a gain variable signal source 5 and then supplied to a current adding circuit 3. A bias variable voltage source 6 is connected to the circuit 3 for execution of the bias control. The output of the circuit 3 is amplified by an amplifier circuit 4 for signal amplification. Then a desired signal is delivered. In other words, the circuit 2 is connected directly with the circuit 4 via the circuit 3 without using a coupling capacitor. Thus the gain control and the bias control are carried out independently of each other. The circuit 3 supplies the signal underwent the gain control through the circuit 2 and gives the voltage/current conversion to the gain controlled signal together with the bias control through the voltage source 6. Then the signal underwent both the gain and bias controls is delivered.

73. 发明专利

JPS6138883B2 失效
公开(公告)号：JPS6138883B2
公开(公告)日：1986-09-01
申请号：JP7815679
申请日：1979-06-22
申请人： HITACHI LTD
发明人： KATO KAZUO
IPC分类号： H03F3/34 , H03F1/30

74. 发明专利

JPS6122886B2 JPS6122886B2 - 失效
公开(公告)号：JPS6122886B2
公开(公告)日：1986-06-03
申请号：JP6769978
申请日：1978-06-07
申请人： Hitachi Ltd
发明人： SASE TAKASHI , KATO KAZUO
IPC分类号： G01D3/028 , G01D5/16

75. 发明专利

JPS609427B2 失效
公开(公告)号：JPS609427B2
公开(公告)日：1985-03-09
申请号：JP9825582
申请日：1982-06-07
申请人： HITACHI LTD
发明人： KATO KAZUO
IPC分类号： H03K5/04 , H02M3/28 , H02M3/335 , H03K3/017

76. 发明专利

JPS5853771B2 JPS5853771B2 - 失效
公开(公告)号：JPS5853771B2
公开(公告)日：1983-12-01
申请号：JP12848578
申请日：1978-10-20
申请人： Hitachi Ltd
发明人： SASE TAKASHI , KATO KAZUO , YANAKA MASAO , MURAYAMA NORIO
IPC分类号： G05B15/02 , G05B15/00 , G06F3/00 , G06F13/00

77. 发明专利

JPS5838009B2 失效
公开(公告)号：JPS5838009B2
公开(公告)日：1983-08-19
申请号：JP11921276
申请日：1976-10-04
申请人： HITACHI LTD
发明人： SASE TAKASHI , KATO KAZUO
IPC分类号： H03H11/02 , H03H11/38

78. 发明专利

JPS5181933A 失效
公开(公告)号：JPS5181933A
公开(公告)日：1976-07-17
申请号：JP711375
申请日：1975-01-17
申请人： HITACHI LTD
发明人： KATO KAZUO
IPC分类号： H01F19/04 , H01F19/00

79. 发明专利

JP2002252980A CURRENT TRANSFORMER INPUT TYPE POWER UNIT 失效
公开(公告)号：JP2002252980A
公开(公告)日：2002-09-06
申请号：JP2001051259
申请日：2001-02-26
申请人： HITACHI LTD
发明人： WATANABE MASAHIRO , KATO KAZUO , OGAWA KENJI , UENO ISAO
IPC分类号： H02M7/12 , H02M7/217 , H02M7/219
摘要： PROBLEM TO BE SOLVED: To provide a current transformer input type DC power unit, which has a simple constitution and a less power loss. SOLUTION: An AC switch 20 for short-circuiting a secondary winding 120 of a current transformer 10, comprises of field-effect transistors 211 to 214, which is a low on-resistance switch having no offset voltage generated at the time of current rise, so that the power loss occurring at the time of an excessive input is reduced, and the volt-ampere at the time of the maximum operation of the secondary winding 120 is limited to a minimum so that the current transformer is miniaturized.

80. 发明专利

JP2001333534A CONTROLLER FOR AC-TO-DC CONVERTER 失效
公开(公告)号：JP2001333534A
公开(公告)日：2001-11-30
申请号：JP2000148386
申请日：2000-05-19
申请人： KANSAI ELECTRIC POWER CO , SHIKOKU ELEC POWER , ELECTRIC POWER DEV CO , HITACHI LTD , TOSHIBA CORP
发明人： AZUMA MASAKI , UEHARA NOBUKAZU , KATO KAZUO , SEKOGUCHI MASAHIRO , GOTO MASUO , TANOMURA KENICHI , ARAI JUNICHI
IPC分类号： H02J3/24 , H02J3/36 , H02M7/48
摘要： PROBLEM TO BE SOLVED: To see that it does not exert influence upon the control of firing angle of a system and a DC transmission system, in system conditions where axially torsional resonance phenomena do not occur, and precisely suppress the diffusion of the vibration of shaft torsional resonance phenomena, in system condition that the shaft torsional resonance phenomena occur. SOLUTION: This controller is equipped with an shaft torsional vibration component extracting means which detects the quantity of electricity in the vicinity of a conversion place and extracts the shaft torsional vibration components of a turbine generator, a starting signal computing means, which computes and outputs a starting signal for an shaft torsional resonance phenomena suppressive control circuit for suppressing the shaft torsional resonance phenomena of a turbine generator from the shaft torsional vibration components extracted by the shaft torsional vibration extracting means, a stop signal computing means which computes and outputs a stop signal for an shaft torsional resonance phenomena suppressing control circuit from the shaft torsional vibration components extracted by the shaft torsional vibration component extracting means, and a starting/stopping means which receives the start signal from the start signal computing means or the stop signal from the start signal computing means and starts or stops the shaft torsional resonance phenomena suppressing control circuit.

你已经成功收藏专利！

检索式保存成功!

IPRDB

热门服务

关于我们

友情链接

联系方式