US3870938A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Waveform generator and phase shifter
Assignee: Allard Way Holdings Ltd
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Filing: 1972-04-17
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Granted: 1975-03-11
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Expires: 1992-04-17
Abstract
Abstract This invention has the overall objective of providing a plurality of sets of synchro signals, each set being a set of AC signals of fixed frequency and phase, amplitude modulated in accordance with a sinusoidal function of an arbitrarily variable phase angle. This is achieved by generating signals of fixed amplitude and suitably controlled phase, and summing them. The variable phase signals are generated by a digital technique, a sequence of ''''1''s'''' suitably spaced being stored in a fixed store and read out into recirculating shift registers with suitable phasing. The digital sequence then drives switches to generate signals of accurately known amplitude. Several sets of signals can be generated in turn with the majority of the circuit being shared among all sets.
Inventors
- 👤 Michael John Tooze
- 👤 Peter Michael Knight
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:18
CPC Classifications
G; G06; G06F; G06F1/00; G06F1/02; G06F1/03; G06F1/0321; H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/099; H03L7/0991; H03L7/0992; G06F2101/00; G06F2101/04
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
167 words
A waveform generator which, in response to an input A.C. reference signal having a predetermined frequency and phase angle and an input signal representing a variable angle, develops a sinusoidal output signal which is phase locked to the input reference signal and whose amplitude is a sinusoidal function of said angle represented by the input signal, comprising: a digital store for storing a digital representation of a sinusoidal waveform; means for reading out the contents of said store; a clock generator for producing a clock signal which is synchronised to the reference signal and which controls said read-out means so as to produce two sinusoidal signals of fixed amplitude at the frequency oF the reference signal and having phase angles which are respectively advanced and retarded with respect to the phase angle of the reference signal by said variable angle; and summing means having a pair of input terminals for receiving said sinusoidal signals for summing said sinusoidal signals, whereby said desired sinusoidal output signal is produced.
Claim 2
Dependent Claim
167 words
A waveform generator which, in response to an input A.C. reference signal having a predetermined frequency and phase angle and an input signal representing a variable angle, develops a sinusoidal output signal which is phase locked to the input reference signal and whose amplitude is a sinusoidal function of said angle represented by the input signal, comprising: a digital store for storing a digital representation of a sinusoidal waveform; means for reading out the contents of said store; a clock generator for producing a clock signal which is synchronised to the reference signal and which controls said read-out means so as to produce two sinusoidal signals of fixed amplitude at the frequency oF the reference signal and having phase angles which are respectively advanced and retarded with respect to the phase angle of the reference signal by said variable angle; and summing means having a pair of input terminals for receiving said sinusoidal signals for summing said sinusoidal signals, whereby said desired sinusoidal output signal is produced.
Claim 3
Dependent Claim
167 words
A waveform generator which, in response to an input A.C. reference signal having a predetermined frequency and phase angle and an input signal representing a variable angle, develops a sinusoidal output signal which is phase locked to the input reference signal and whose amplitude is a sinusoidal function of said angle represented by the input signal, comprising: a digital store for storing a digital representation of a sinusoidal waveform; means for reading out the contents of said store; a clock generator for producing a clock signal which is synchronised to the reference signal and which controls said read-out means so as to produce two sinusoidal signals of fixed amplitude at the frequency oF the reference signal and having phase angles which are respectively advanced and retarded with respect to the phase angle of the reference signal by said variable angle; and summing means having a pair of input terminals for receiving said sinusoidal signals for summing said sinusoidal signals, whereby said desired sinusoidal output signal is produced.
Claim 4
Dependent Claim
167 words
A waveform generator which, in response to an input A.C. reference signal having a predetermined frequency and phase angle and an input signal representing a variable angle, develops a sinusoidal output signal which is phase locked to the input reference signal and whose amplitude is a sinusoidal function of said angle represented by the input signal, comprising: a digital store for storing a digital representation of a sinusoidal waveform; means for reading out the contents of said store; a clock generator for producing a clock signal which is synchronised to the reference signal and which controls said read-out means so as to produce two sinusoidal signals of fixed amplitude at the frequency oF the reference signal and having phase angles which are respectively advanced and retarded with respect to the phase angle of the reference signal by said variable angle; and summing means having a pair of input terminals for receiving said sinusoidal signals for summing said sinusoidal signals, whereby said desired sinusoidal output signal is produced.
Claim 5
Dependent Claim
73 words
A waveform generator according to claim 1, in which the store is a digital 2n stage store, the clock signal has a frequency equal to 2n times the reference signal frequency and the store is read out beginning at stages determined by an n-bit number representative of the desired phase angle and its complement, whereby the store read-out consists of alternate pulses forming two separate trains which are representative of said sinusoidal signals.
Claim 6
Dependent Claim
80 words
A waveform generator according to claim 2, in which the means for reading out the contents of the store comprises an input register for containing said n-bit number, first and second cyclic counters whose counting rate is controlled by the clock signal, an OR gate having its inputs connected to the outputs from the counters, an address decoder having its input connected to the OR gate and a complementing circuit connected between the input register and one of the counters.
Claim 7
Dependent Claim
31 words
A function generator waveform, generator according to claim 2 in which the store read-out is applied to gating circuits which are controlled by the clock signal to respectively pass alternate pulses.
Claim 8
Dependent Claim
35 words
A waveform generator according to claim 4 in which the outputs from the gating circuits are applied to recirculating shift registers, whereby the store needs to be read only once for a given phase angle.
Claim 9
Dependent Claim
22 words
A waveform generator according to claim 5, in which the shift registers are tapped to provide sinusoidal signals having different phase angles.
Claim 10
Dependent Claim
41 words
A waveform generator according to claim 5 in which the outputs from the shift registers are fed to respective precision switches which are supplied with precisely controlled reference voltages to produce outputs which are digital pulse trains of precisely controlled amplitude.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |