US3576491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resistance measuring bridge circuit including output gating means
Assignee: THORNTON ASSOCIATES Inc
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Filing: 1968-08-12
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Granted: 1971-04-27
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Expires: 1988-08-12
Abstract
Abstract In a conductivity bridge a switching system is employed to allow only selected portions of the bridge output signal to pass through the output indicator meter. More specifically, initial portion of the signal waveform output, corresponding to the time during which the stray capacitance in the circuit is becoming fully charged, is prevented from passing through the meter, thereby eliminating the effect of such capacitance in the circuit and thus yielding a more accurate measurement of an unknown resistance.
Inventors
- 👤 Richard D Thornton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:57
CPC Classifications
G; G01; G01R; G01R17/00; G01R17/10; G01R17/105
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
106 words
A resistance measuring circuit comprising A. bridge circuit 1. including an unknown resistance to be measured, 2. having a reactance associated therewith, B. means connected to apply to said bridge circuit as an input thereof a sequence of pulses having a constant peak for an interval greater than the time required for substantially fully charging the reactances associated with said bridge, C. output means, and D. gating means responsive to signals derived from said sequence of pulses for passing the output signal of said bridge to said output means only during a selected latter portion of each said interval after said reactance is substantially fully charged.
Claim 2
Dependent Claim
106 words
A resistance measuring circuit comprising A. bridge circuit 1. including an unknown resistance to be measured, 2. having a reactance associated therewith, B. means connected to apply to said bridge circuit as an input thereof a sequence of pulses having a constant peak for an interval greater than the time required for substantially fully charging the reactances associated with said bridge, C. output means, and D. gating means responsive to signals derived from said sequence of pulses for passing the output signal of said bridge to said output means only during a selected latter portion of each said interval after said reactance is substantially fully charged.
Claim 3
Dependent Claim
89 words
having a reactance associated therewith, B. means connected to apply to said bridge circuit as an input thereof a sequence of pulses having a constant peak for an interval greater than the time required for substantially fully charging the reactances associated with said bridge, C. output means, and D. gating means responsive to signals derived from said sequence of pulses for passing the output signal of said bridge to said output means only during a selected latter portion of each said interval after said reactance is substantially fully charged.
Claim 4
Dependent Claim
89 words
having a reactance associated therewith, B. means connected to apply to said bridge circuit as an input thereof a sequence of pulses having a constant peak for an interval greater than the time required for substantially fully charging the reactances associated with said bridge, C. output means, and D. gating means responsive to signals derived from said sequence of pulses for passing the output signal of said bridge to said output means only during a selected latter portion of each said interval after said reactance is substantially fully charged.
Claim 5
Dependent Claim
93 words
The circuit defined in claim 1 A. in which said pulses are in the form of a square wave, B. in which said gating means passes said bridge output signal through said output means in a first direction during said portions of said square wave when said square wave has one polarity and in the opposite direction during said portions of said square wave when said square wave has the opposite polarity, and C. in which said output means responds to the difference in current therethrough during alternate half-cycles of said square wave.
Claim 6
Dependent Claim
30 words
to pass to the respective transistors the output of said multivibrator, thereby to cause said transistors to conduct during the latter halves of alternate half-cycles of said square wave signal.
Claim 7
Dependent Claim
30 words
to pass to the respective transistors the output of said multivibrator, thereby to cause said transistors to conduct during the latter halves of alternate half-cycles of said square wave signal.
Claim 8
Dependent Claim
63 words
The circuit defined in claim 2 including A. biasing means connected to convert the output of said bridge to a unidirectional signal by adding a DC level thereto. B. switching means arranged to connect said output means into said circuit in one direction during square wave half-cycles of one polarity and in the other direction during the other half-cycles of said square wave.
Claim 9
Dependent Claim
20 words
The circuit defined in claim 3 including a direct coupled amplifier connected between said biasing means and said output means.
Claim 10
Dependent Claim
73 words
The circuit defined In claim 3 A. including a square wave generator, B. including a frequency divider connected to halve the frequency of said generator to provide said square wave input signal for said bridge, C. in which said switching means includes a pair of transistors connected to apply the output signal of said bridge circuit to said output means in opposite directions when they conduct, and D. including a pair of gates,
References Cited (Backward Citations)
CA768294A
Cited
US3076338A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |