US3611129A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low frequency measuring circuit
Assignee: Vyzk Ustav Zdravot Tech
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Filing: 1969-01-31
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Granted: 1971-10-05
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Expires: 1989-01-31
Abstract
Abstract An amplifier is coupled to the filter and connected to the frequency-measuring indicator of a frequency meter. A coupling circuit couples the filter to the amplifier. The amplifier is a transistor and has a current amplification factor which is highly dependent upon the instantaneous working point of the amplifier whereby the equivalent effect of the filter and the amplifier is a function of the direct current component output of the filter, and the filter and amplifier function as a filter with an automatically controlled filtering effect.
Inventors
- 👤 Jiri Simurda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:41
CPC Classifications
H; H03; H03G; H03G5/00; H03G5/16; H03G5/18; H03G5/22; A; A61; A61B; A61B5/00; A61B5/02; A61B5/024; G; G01; G01R; G01R23/00; G01R23/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
217 words
A frequency-metering circuit arrangement comprising pulse input means for providing a sequence of uniform area current pulses of uniform amplitude and uniform duration at a low frequency indicative of the frequency to be measured; filter means having a first input connected to said pulse input means for converting the pulses provided by said pulse input means to a substantially direct current component proportional to the frequency of the input pulses, said direct current component having a residual ripple, said filter means having a second input and an output; frequency-measuring means connected to the output of said filter means for indicating the magnitude of said direct current component as an indication of the frequency of the input pulses; amplifier means having an input and an output, said output being coupled to the second input of said filter means and to said frequency measuring means; and coupling means connecting the output of said filter means to the input of said amplifier means, said amplifier means having a current amplification factor which is highly dependent upon the instantaneous working point of said amplifier means whereby the equivalent effect of said filter means and said amplifier means is a function of said direct component, and said filter means and amplifier means function as a filter with an automatically controlled filtering effect.
Claim 2
Dependent Claim
217 words
A frequency-metering circuit arrangement comprising pulse input means for providing a sequence of uniform area current pulses of uniform amplitude and uniform duration at a low frequency indicative of the frequency to be measured; filter means having a first input connected to said pulse input means for converting the pulses provided by said pulse input means to a substantially direct current component proportional to the frequency of the input pulses, said direct current component having a residual ripple, said filter means having a second input and an output; frequency-measuring means connected to the output of said filter means for indicating the magnitude of said direct current component as an indication of the frequency of the input pulses; amplifier means having an input and an output, said output being coupled to the second input of said filter means and to said frequency measuring means; and coupling means connecting the output of said filter means to the input of said amplifier means, said amplifier means having a current amplification factor which is highly dependent upon the instantaneous working point of said amplifier means whereby the equivalent effect of said filter means and said amplifier means is a function of said direct component, and said filter means and amplifier means function as a filter with an automatically controlled filtering effect.
Claim 3
Dependent Claim
29 words
A frequency-metering circuit arrangement as claimed in claim 1, wherein said filter means comprises a low-pass filter and said filter means and amplifier means function as a low-pass filter.
Claim 4
Dependent Claim
48 words
A frequency-metering circuit arrangement as claimed in claim 1, wherein the working point of said amplifier means is controlled by said direct current component via said coupling means in a manner whereby said amplifier means functions as an amplifier throughout the entire range of frequEncies to be measured.
Claim 5
Dependent Claim
47 words
A frequency-metering circuit arrangement as claimed in claim 1, wherein said amplifier means amplifies and inverts the residual ripple of said direct current component and combines the inverted amplified ripple with the ripple of said direct current component to increase the filtering action of said filter means.
Claim 6
Dependent Claim
35 words
A frequency-metering circuit arrangement as claimed in claim 1, wherein the amplification factor of said amplifier means increases and the filtering effect of said filter means and amplifier means increases as the measured frequency decreases.
Claim 7
Dependent Claim
25 words
A frequency-metering circuit arrangement as claimed in claim 1, wherein said coupling means comprises a resistor and a capacitor connected in parallel with each other.
Claim 8
Dependent Claim
22 words
A frequency-metering circuit arrangement as claimed in claim 1, wherein said amplifier means comprises a transistor having emitter, collector and base electrodes.
Claim 9
Dependent Claim
61 words
A frequency meter circuit arrangement as claimed in claim 1 wherein said amplifier means comprises a transistor having a collector electrode connected in common to one terminal of said frequency-measuring means, and said pulse input means, an emitter electrode connected to said pulse input means, and a base electrode coupled to the output of said filter means via said coupling means.
Claim 10
Dependent Claim
75 words
A frequency-metering circuit arrangement as claimed in claim 8, wherein said filter means has an input and an output said input being connected to said collector electrode the output of said filter means being directly connected to the other terminal of said frequency-measuring means, and further comprising a load resistor connected between the collector electrode of said transistor and the common connection with said one terminal of said frequency-measuring means and said pulse input means.
Claim 11
Dependent Claim
57 words
A frequency meter circuit arrangement as claimed in claim 9, wherein the amplification factor of said transistor increases with an increase in magnitude of said direct current component, said coupling means comprises a resistor and a capacitor connected in parallel with each other, and said filter means comprises a resistor and a capacitor connected to each other.
References Cited (Backward Citations)
US3350637A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-04 | 1975-04-05 | 1975-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-04 | 1979-04-05 | 1979-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-04 | 1983-04-05 | 1983-10-05 | $7700.00 | Window Closed / Lapsed |