US3622864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and circuitry for generating and holding proportional against input power variations a current and a resulting voltage for particle analyzer
Assignee: Coulter Electronics Inc
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Filing: 1969-07-09
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Granted: 1971-11-23
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Expires: 1989-07-09
Abstract
Abstract To improve the precision operation of a ''''Coulter Counter'''' particle analyzer, which is subject to small magnitude, yet statistically important input power voltage changes that are random in nature and magnitude, the current applied to the microscopic sensing aperture and the voltage applied to the threshold circuits, which monitor and respond to the amplitudes of the particle signals derived from the sensing aperture, are caused to track one another; so that variations of input power do not adversely affect the precision output of the particle analyzer. In series with both the sensing aperture circuit and the threshold circuits is the power supply, a polarity control switch and a current sensing resistor. Interposed between the current sensing resistor and the threshold circuits is an absolute value amplifier, which applies to the threshold circuits a voltage proportional to the aperture current. Additionally, the output from the absolute value amplifier is compared with an arbitrary voltage reference, and the result of the comparison is employed to determine both the aperture current and the threshold voltage.
Inventors
- 👤 William A Claps
- 👤 David R Figueroa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:12
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/10; G01N15/1031; G01N15/12; G01N15/131; G01N15/132
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
121 words
A method for generating from a common power supply, which is subject to random power line changes, a current for a particle analyzing aperture circuit and a resulting voltage for threshold circuits of a particle analyzer, such that said current and said voltage remain proportional to one another to a high degree of precision despite said power line changes, comprising the steps of: sensing the current which is being supplied to the aperture circuit by the power supply, switching periodically the polarity of the output from the power supply prior to said sensing, employing the sensed current to define a sensed voltage, deriving the absolute value of said sensed voltage, and applying said absolute value of voltage to the threshold circuits.
Claim 2
Independent Claim
121 words
A method for generating from a common power supply, which is subject to random power line changes, a current for a particle analyzing aperture circuit and a resulting voltage for threshold circuits of a particle analyzer, such that said current and said voltage remain proportional to one another to a high degree of precision despite said power line changes, comprising the steps of: sensing the current which is being supplied to the aperture circuit by the power supply, switching periodically the polarity of the output from the power supply prior to said sensing, employing the sensed current to define a sensed voltage, deriving the absolute value of said sensed voltage, and applying said absolute value of voltage to the threshold circuits.
Claim 3
Dependent Claim
49 words
A method according to claim 1 further comprising comparing said absolute value of voltage with an arbitrary voltage reference, and feeding the result of said comparing back to the power supply such that the nominal levels of said current and said voltage are determined by the arbitrary voltage reference.
Claim 4
Dependent Claim
27 words
A method according to claim 2 further comprising amplifying the gain of the result of said comparing for increasing the stability of said current and said voltage.
Claim 5
Dependent Claim
22 words
A method according to claim 1 further comprising inverting the phase of the output of the aperture circuit synchronously with said switching.
Claim 6
Dependent Claim
16 words
A method according to claim 4 in which said sensing is accomplished by a resistive impedance.
Claim 7
Dependent Claim
49 words
A method according to claim 5 further comprising filtering the output of the power supply prior to said sensing, coupling by resistive impedance the resultant of said filtering to the aperture circuit, and regulating the resistive sensing impedance to be significantly small with respect to the resistive coupling impedance.
Claim 8
Dependent Claim
124 words
Circuitry for the generation from a common power supply, which is subject to random power changes, a current and a resulting voltage for application to respectively different circuitry elements, such that said current and said voltage are held closely proportional to one another despite said random power changes, comprising: means for sensing said current as it is being applied from said power supply to a first of said circuitry elements, a polarity reversing switch interposed between said power supply and said current sensing means, for periodic operation to reduce the polarization tendency of at least said first circuitry element, and means for measuring said sensed current and deriving therefrom a proportional voltage of absolute value for application to a second of said circuitry elements.
Claim 9
Dependent Claim
124 words
Circuitry for the generation from a common power supply, which is subject to random power changes, a current and a resulting voltage for application to respectively different circuitry elements, such that said current and said voltage are held closely proportional to one another despite said random power changes, comprising: means for sensing said current as it is being applied from said power supply to a first of said circuitry elements, a polarity reversing switch interposed between said power supply and said current sensing means, for periodic operation to reduce the polarization tendency of at least said first circuitry element, and means for measuring said sensed current and deriving therefrom a proportional voltage of absolute value for application to a second of said circuitry elements.
Claim 10
Dependent Claim
41 words
Circuitry according to claim 7 wherein said sensing means and said measuring means in combination comprise a resistor having one end connected to said first circuitry element and its other end coupled to said power supply and an absolute value amplifier.
Claim 11
Dependent Claim
37 words
Circuitry according to claim 8 wherein an aperture circuit for a particle analyzer comprises said first circuitry element, at least one threshold circuit comprises said second circuitry element, and said one end of said resistor is grounded.
Claim 12
Dependent Claim
52 words
Circuitry according to claim 9 further comprising filter means coupled between said power supply, said aperture circuit, and said resistor, a coupling resistor connecting the output of said filter to said aperture circuit, and the impedance of said sensing and measuring resistor being significantly smaller than the impedance of said coupling resistor.
Claim 13
Dependent Claim
62 words
Circuitry according to claim 7 further comprising a phase inverter coupled to the output of said first circuitry element, and ganged switching means selectively connectable to said phase inverter in response to operation of said polarity reversing switch, whereby said phase inverter is placed operatively into said generation circuitry when said polarity switch enables the passage of power of one selected polarity.
Claim 14
Dependent Claim
65 words
Circuitry according to claim 7 wherein said power supply comprises an oscillator, a bistable device for shaping the output of said oscillator into square waves, a power amplifier logically parallel to said bistable device, and a transformer having its primary coupled to be responsive to both said bistable device and said power amplifier, and its secondary coupled to the input of said polarity reversing switch.
Claim 15
Dependent Claim
61 words
Circuitry according to claim 7 further comprising a comparator having one input for receiving said voltage of absolute value and an output coupled to said power supply in a feedback mode, and a voltage reference having an output coupled to another input to said comparator, whereby the two inputs define an error signal that is applied to regulate said power supply.
Claim 16
Dependent Claim
29 words
Circuitry according to claim 13 further comprising a gain amplifier interposed between the output of said comparator and said power supply for increasing the stability of said generation circuitry.
Claim 17
Dependent Claim
62 words
Circuitry according to claim 14 further comprising a phase inverter coupled to the output of said first circuitry element, and ganged switching means selectively connectable to said phase inverter in response to operation of said polarity reversing switch, whereby said phase inverter is placed operatively into said generation circuitry when said polarity switch enables the passage of power of one selected polarity.
Claim 18
Dependent Claim
29 words
Circuitry according to claim 15 wherein an aperture circuit for a particle analyzer comprises said first circuitry element, and at least one threshold circuit comprises said second circuitry element.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |