US3829962A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Active trimming of film deposited oscillators
Assignee: AG Communication Systems Corp
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Filing: 1972-12-04
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Granted: 1974-08-20
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Expires: 1992-12-04
Abstract
Abstract A system for calibrating oscillators by trimming film resistors includes a network for energizing a film oscillator under simulated operating conditions, with a digital counter measuring the frequency of the active oscillator by counting with a zero axis register the number of times the oscillator signal waveform crosses the zero axis of a zero axis detector and thereafter converting to frequency by dividing the resulting count by the count of a simultaneously triggered time register, comparing this measured frequency to a predetermined frequency to be achieved, and physically modifying the film resistor in response to the frequency comparison to correct the frequency of the film oscillator.
Inventors
- 👤 J Simonelic
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:04
CPC Classifications
H; H03; H03B; H03B5/00; H03B5/02; H01; H01C; H01C17/00; H01C17/22; H01C17/24; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49004; Y10T29/49082
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
179 words
A method of actively trimming an oscillator having a film resistor comprising the steps of monitoring the output of the oscillator, cumulatively counting the number of times the signal waveform is detected to cross a zero axis reference in a given direction between a first crossing of said zero axis and a preselected succeeding crossing of said waveform, simultaneously cumulatively counting the number of occurrences of clock timing pulses that occur between said first crossing and said succeeding crossing of said waveform, dividing said number of waveform zero axis crossings by said accumulated count of clock pulses to convert said number of waveform crossings to measured frequency of a digital format, comparing the measured frequency to a preset frequency of a digital format, and either removing a portion of said film resistor in response to said comparing when the measured frequency is in a first predetermined relation to said preset frequency, said removing occurring during said monitoring while oscillation continues, or rejecting said film resistor when the measured frequency is in a second predetermined relation to said preset frequency.
Claim 2
Independent Claim
179 words
A method of actively trimming an oscillator having a film resistor comprising the steps of monitoring the output of the oscillator, cumulatively counting the number of times the signal waveform is detected to cross a zero axis reference in a given direction between a first crossing of said zero axis and a preselected succeeding crossing of said waveform, simultaneously cumulatively counting the number of occurrences of clock timing pulses that occur between said first crossing and said succeeding crossing of said waveform, dividing said number of waveform zero axis crossings by said accumulated count of clock pulses to convert said number of waveform crossings to measured frequency of a digital format, comparing the measured frequency to a preset frequency of a digital format, and either removing a portion of said film resistor in response to said comparing when the measured frequency is in a first predetermined relation to said preset frequency, said removing occurring during said monitoring while oscillation continues, or rejecting said film resistor when the measured frequency is in a second predetermined relation to said preset frequency.
Claim 3
Dependent Claim
81 words
The method in accordance with claim 1 wherein a first binary register counts the number of times the waveform of the signal crosses the zero axis, a secondary binary register receives clock pulses from a master oscillator and accumulates the pulses, and said first register starts the second register when said waveform crosses said zero axis in said given direction and stops said second register when at a predetermined succeeding time said waveform crosses said zero axis in said given direction.
Claim 4
Independent Claim
169 words
A system for the active trimming of a film oscillator having a film resistor, comprising zero crossing detector means for detecting when the waveform of the oscillator output crosses the zero axis, first binary register means for cumulatively counting the zero crossings in a given direction between a first crossing of said zero axis and a preselected succeeding crossing of said waveform, second binary register means for simultaneously cumulatively counting the number of occurrences of clock timing pulses that occur to relate said waveform zero crossings to units of time, binary divider means for dividing the number of waveform zero crossings in said given direction by the number of clock pulses to determine the measured frequency of the oscillator signal, reference means for supplying a preset frequency, magnitude comparator means for comparing said measured frequency to said preset frequency, and trimming means for removing a portion of said film resistor in response to said comparing means when said oscillator frequency is in a predetermined relation to said preset frequency.
Claim 5
Independent Claim
169 words
A system for the active trimming of a film oscillator having a film resistor, comprising zero crossing detector means for detecting when the waveform of the oscillator output crosses the zero axis, first binary register means for cumulatively counting the zero crossings in a given direction between a first crossing of said zero axis and a preselected succeeding crossing of said waveform, second binary register means for simultaneously cumulatively counting the number of occurrences of clock timing pulses that occur to relate said waveform zero crossings to units of time, binary divider means for dividing the number of waveform zero crossings in said given direction by the number of clock pulses to determine the measured frequency of the oscillator signal, reference means for supplying a preset frequency, magnitude comparator means for comparing said measured frequency to said preset frequency, and trimming means for removing a portion of said film resistor in response to said comparing means when said oscillator frequency is in a predetermined relation to said preset frequency.
Claim 6
Dependent Claim
53 words
The method in accordance with claim 1 wherein said step of counting the number of zero axis crossings of said waveform occurs between the first crossing of said zero axis and an immediately succeeding crossing of said zero axis for obtaining the measured frequency of said signal waveform in one complete cycle thereof.
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) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |