GB1375060A – – Google Patents
GB1375060A – – Google Patents
Info
Publication number
GB1375060A
GB1375060A
GB5038372A
GB5038372A
GB1375060A
GB 1375060 A
GB1375060 A
GB 1375060A
GB 5038372 A
GB5038372 A
GB 5038372A
GB 5038372 A
GB5038372 A
GB 5038372A
GB 1375060 A
GB1375060 A
GB 1375060A
Authority
GB
United Kingdom
Prior art keywords
signal
counters
amplifier
read
attenuator
Prior art date
1971-11-04
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB5038372A
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1971-11-04
Filing date
1972-11-01
Publication date
1974-11-27
1972-11-01
Application filed
filed
Critical
1974-11-27
Publication of GB1375060A
publication
Critical
patent/GB1375060A/en
Status
Expired
legal-status
Critical
Current
Links
Espacenet
Global Dossier
Discuss
Classifications
H—ELECTRICITY
H03—ELECTRONIC CIRCUITRY
H03G—CONTROL OF AMPLIFICATION
H03G3/00—Gain control in amplifiers or frequency changers without distortion of the input signal
H03G3/20—Automatic control
H03G3/30—Automatic control in amplifiers having semiconductor devices
H03G3/3005—Automatic control in amplifiers having semiconductor devices in amplifiers suitable for low-frequencies, e.g. audio amplifiers
H03G3/301—Automatic control in amplifiers having semiconductor devices in amplifiers suitable for low-frequencies, e.g. audio amplifiers the gain being continuously variable
H03G3/3015—Automatic control in amplifiers having semiconductor devices in amplifiers suitable for low-frequencies, e.g. audio amplifiers the gain being continuously variable using diodes or transistors
G—PHYSICS
G01—MEASURING; TESTING
G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
G01N15/10—Investigating individual particles
G01N15/12—Coulter-counters
G—PHYSICS
G06—COMPUTING; CALCULATING OR COUNTING
G06G—ANALOGUE COMPUTERS
G06G7/00—Devices in which the computing operation is performed by varying electric or magnetic quantities
G06G7/48—Analogue computers for specific processes, systems or devices, e.g. simulators
G06G7/75—Analogue computers for specific processes, systems or devices, e.g. simulators for component analysis, e.g. of mixtures, of colours
Abstract
1375060 Voltage measuring COULTER ELECTRONICS Ltd 1 Nov 1972 [4 Nov 1971] 50383/72 Heading G1U [Also in Division H4] After each signal of a sequence of time-varying signals whose maximum amplitudes are expected to increase progressively along the sequence, the gain of an amplifier is adjusted in such a way as to attempt to bring the maximum value of each signal to a common reference level. Three amplifying arrangements are described for this purpose in each of which a fixed gain amplifier 74 is preceded by an attenuator which is adjusted after each signal; in both the first Fig.3 and the second Fig. 5 (not shown) the attenuator is constituted by a potential divider comprising a fixed resistor 92, Fig.3, and a variable resistor, FET 96, taken down to a reference potential on a capacitor 132, the potential divider being adjusted after each signal has been amplified by applying the maximum value of the signal to the divider, comparing 108 the output of the amplifier 74 with a pre-set reference level 114 and appropriately varying the potential stored on a capacitor 120, and hence the effective impedance of the FET, until equality obtains; and in the third, Fig.6, the attenuator is constituted by a ladder attenuator 334 controlled by a counter 322 which is stepped in accordance with the result of the comparison 108 of the amplified maximum signal and the reference level 114. The particular application described relates to a particle size analyzing system, in which the sizes of a sequence of particles are determined 10, Fig.1, and for each particle one of a plurality of counters or other devices, 12, in accordance with the range in which the particle size lies, has its contents augmented by unity. Periodically the contents of the counters are read sequentially 16, 38, to produce a sequence of dots representing a frequency distribution curve on a c.r.t. or graphical plotter. Since particle sizes are continually being determined, all counts are continually increasing, so that in the absence of the invention a sequence of read-outs from the counter would probably look as shown at 61, 62, 63, 64, Fig.2. In addition to the basic range counters, the system also includes a further set of counters or integrators 20, each of which corresponds to a particular particle size and is augmented by unity when a particle less than that size is encountered. These counters are also periodically sequentially read to produce a cumulative frequency distribution curve of the form shown at 60, Fig.2. Clearly, the count, in the ‘top’ counter (i.e. the extreme top right-hand point of curve (60) corresponds to the total number of particles analyzed, and it is this count which is used by the invention to control the input attenuator to amplifier 74, Figs.3, 6, so that the maximum point on the cumulative frequency distribution curve 60, Fig.3, always occurs at a reference level labelled 100% on the c.r.t. The system has an operating cycle consisting of four places. In phase I, Fig.4, the basic range counters are read out. Their signals A138, Fig.4, are passed on lead 24, Fig.3, via a closed switch 86 to the potential divider 92, 98, and the attenuated signal B144, Fig.4 is amplified 74 to produce an output signal at a point 32, C146 Fig.4, which is displayed on the c.r.t. Phase II is similar except that the cumulative frequency counters are read A140, attenuated B148 and amplified to give signal C146. In phase III the input to amplifier 74 is earthed by the switch 86 and the output, via a closed switch 130, is compared with ground 80 so as to provide a zero off-set voltage which is stored on capacitor 132. In phase IV the attenuated output B160, Fig.2 from the ‘top’ cumulative frequency counter is reapplied to the amplifier and the output C162 is compared with the reference level 114 to adjust the effective impedance of FET 96. This process repeats and, as can be seen, even though successive read-out signals A, Fig. 4, progressively become larger, the maximum amplitude produced by the amplifier 74, Cl Fig.4, remains substantially constant.
GB5038372A
1971-11-04
1972-11-01
Expired
GB1375060A
(en)
Applications Claiming Priority (1)
Application Number
Priority Date
Filing Date
Title
US19572271A
1971-11-04
1971-11-04
Publications (1)
Publication Number
Publication Date
GB1375060A
true
GB1375060A
(en)
1974-11-27
Family
ID=22722517
Family Applications (1)
Application Number
Title
Priority Date
Filing Date
GB5038372A
Expired
GB1375060A
(en)
1971-11-04
1972-11-01
Country Status (6)
Country
Link
JP
(1)
JPS539560B2
(en)
CA
(1)
CA976276A
(en)
FR
(1)
FR2159955A5
(en)
GB
(1)
GB1375060A
(en)
NL
(1)
NL157987B
(en)
ZA
(1)
ZA727769B
(en)
Families Citing this family (1)
* Cited by examiner, † Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
CN107659280B
(en)
*
2017-11-14
2023-10-20
长鑫存储技术有限公司
Time amplifier and semiconductor memory
1972
1972-11-01
NL
NL7214742.A
patent/NL157987B/en
unknown
1972-11-01
ZA
ZA727769A
patent/ZA727769B/en
unknown
1972-11-01
CA
CA155,378A
patent/CA976276A/en
not_active
Expired
1972-11-01
GB
GB5038372A
patent/GB1375060A/en
not_active
Expired
1972-11-01
JP
JP10981272A
patent/JPS539560B2/ja
not_active
Expired
1972-11-02
FR
FR7238724A
patent/FR2159955A5/fr
not_active
Expired
Also Published As
Publication number
Publication date
NL7214742A
(en)
1973-05-08
CA976276A
(en)
1975-10-14
JPS4854982A
(en)
1973-08-02
DE2253758A1
(en)
1973-05-10
DE2253758B2
(en)
1977-03-24
FR2159955A5
(en)
1973-06-22
NL157987B
(en)
1978-09-15
ZA727769B
(en)
1974-06-26
JPS539560B2
(en)
1978-04-06
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Legal Events
Date
Code
Title
Description
1975-04-09
PS
Patent sealed
1982-06-09
PCNP
Patent ceased through non-payment of renewal fee
