US3889198A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voltage waveform generator including feedback arrangement for restoring voltage to initial condition
Assignee: 148074 HOLDINGS CANADA Ltd
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Filing: 1974-02-22
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Granted: 1975-06-10
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Expires: 1994-02-22
Abstract
Abstract Voltage waveform generator including an integrator circuit and a source of reference voltage. Different resistances are connected in order in a series circuit between the source of reference voltage and the input to the integrator circuit to vary the rate at which the output voltage of the integrator circuit changes, thereby producing a desired output voltage waveform. Resistances are switched in and out of the series circuit as determined by the decoded output of a counter which counts periodic clock pulses. A feedback arrangement is coupled between the output and the input of the integrator circuit for restoring the integrator circuit to its starting condition prior to each period during which a waveform is produced.
Inventors
- 👤 John T Lighthall
- 👤 Robert W Thomas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:09
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/26; G06G7/28; H; H03; H03K; H03K4/00; H03K4/02; H03K4/026
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
193 words
Waveform generating apparatus comprising integrating means having an input connection and an output connection; a source of reference potential; a plurality of switch means; a like plurality of resistances; a like plurality of series circuits each connected between said source of reference potential and the input connection of the integrating means, each series circuit including one of the switch means and one of the resistances in series; said integrating means being operable to produce an output voltage at its output connection which varies at a rate determined by the combination of the voltage applied at its input connection through a resistance and the value of the resistance; control means coupled to said plurality of switch means and operable to close and open the switch means of said plurality in a predetermined sequence whereby the value of resistance between the source of reference potential and the input connection of the integrating means is varied; and restoring means coupled to the output connection and to the input connection of the integrating means for producing a predetermined condition at the input connection which causes the integrating means to produce a predetermined voltage at its output connection.
Claim 2
Dependent Claim
193 words
Waveform generating apparatus comprising integrating means having an input connection and an output connection; a source of reference potential; a plurality of switch means; a like plurality of resistances; a like plurality of series circuits each connected between said source of reference potential and the input connection of the integrating means, each series circuit including one of the switch means and one of the resistances in series; said integrating means being operable to produce an output voltage at its output connection which varies at a rate determined by the combination of the voltage applied at its input connection through a resistance and the value of the resistance; control means coupled to said plurality of switch means and operable to close and open the switch means of said plurality in a predetermined sequence whereby the value of resistance between the source of reference potential and the input connection of the integrating means is varied; and restoring means coupled to the output connection and to the input connection of the integrating means for producing a predetermined condition at the input connection which causes the integrating means to produce a predetermined voltage at its output connection.
Claim 3
Dependent Claim
76 words
Waveform generating apparatus in accordance with claim 1 wherein said control means includes timing means operable to permit the control means to close and open the switch means of said plurality in said predetermined sequence during a waveform producing period; said timing means being coupled to said restoring means and being operable to permit the restoring means to operate to produce said predetermined condition at the input connection to the integrating means during a restoring period.
Claim 4
Dependent Claim
144 words
Waveform generating apparatus in accordance with claim 1 wherein said control means includes a source of periodic clock pulses; counting means coupled to the source of periodic clock pulses and operable to count through a recurring sequence of operating states in response to periodic clock pulses; decoding means coupled to said counting means and to each of said plurality of switch means and operable to close and open the switch means of said plurality in a predetermined sequence as determined by the operating states of the counting means; and cycle control means coupled to said counting means for permitting the decoding means to be operable during a waveform producing period; said cycle control means being coupled to said restoring means for permitting the restoring means to operate to produce said predetermined condition at the input connection to the integrating means during a restoring period.
Claim 5
Dependent Claim
137 words
Waveform generating apparatus in accordance with claim 3 wherein said integrating means includes an integrating operational amplifier having first and second input connections and an output connection, said first input connection being coupled to the input connection of the integrating means and said output connection being coupled to the output connection of the integrating means; an integrating capacitance coupled between the first input connection and the output connection of the integrating operational amplifier; the rate of change of the voltage at the output connection of the integrating means during a waveform producing period being directly proportional to the voltage of said source of reference potential and inversely proportional to the value of the resistance connected between said source of reference potential and the input connection of the integrating means and to the value of said integrating capacitance.
Claim 6
Dependent Claim
125 words
Waveform generating apparatus in accordance with claim 4 wherein said restoring means includes a feedback operational amplifier having first and second input connections and an output connection, said first input connection being coupled to the output connection of the integrating means; and feedback switching means coupling the output connection of the feedback operational amplifier to the input connection of the integrating means; said feedback switching means being coupled to said cycle control means and being in an open condition during a waveform producing period whereby the feedback operational amplifier has no effect on the integrating means, and being in a closed condition during a restoring period whereby the feedback operational amplifier operates to produce said predetermined condition at the input connection of the integrating means.
Claim 7
Dependent Claim
118 words
Waveform generating apparatus in accordance with claim 5 wherein said cycle control means produces first and second signal conditions in alternation at an output connection during successive sequences of operating states of said counting means; said decoding means is coupled to the output connection of the cycle control means, said control means being operable during said first signal condition to close and open the switch means of said plurality in said predetermined sequence as determined by the operating states of the counting means and being inoperable during said second signal condition; and said feedback switching means is coupled to the output connection of the cycle control means and is in the open condition during said first signal condition.
Claim 8
Dependent Claim
47 words
Waveform generating apparatus in accordance with claim 6 wherein said feedback switching means is coupled to said counting means and is operable in the closed condition during predetermined operating states of the counting means while the second signal condition is being produced by the cycle control means.
Claim 9
Dependent Claim
69 words
Waveform generating apparatus in accordance with claim 6 including an output terminal; an inverting means coupled between the output connection of the integrating means and the output terminal whereby a voltage waveform which is an inversion of the voltage waveform at the output connection of the integrating means is produced at the output terminal; said output terminal being coupled to the first input connection of the feedback operational amplifier.
Claim 10
Dependent Claim
36 words
Waveform generating apparatus in accordance with claim 8 wherein said first input connection of said integrating operational amplifier is an inverting connection; and said first input connection of said feedback operational amplifier is an inverting connection.
Claim 11
Dependent Claim
80 words
Waveform generating apparatus in Accordance with claim 9 wherein said decoding means is operable to close each of said plurality of switch means one at a time in order during the first half of a waveform producing period and to close each of said plurality of switch means one at a time in reverse order during the second half of a waveform producing period whereby a voltage waveform which is symmetrical about its midpoint is produced at the output terminal.
Claim 12
Dependent Claim
110 words
Waveform generating apparatus in accordance with claim 10 wherein said second input connection of said integrating operational amplifier is a non-inverting connection and is coupled to a second source of reference potential; said second input connection of said feedback operational amplifier is a non-inverting connection and is coupled to said second source of reference potential; and including a resistance connected between said first-mentioned source of reference potential and said second source of reference potential; said resistance having an adjustable tap coupled to the inverting input of the feedback operational amplifier whereby the DC offset of the midpoint of the symmetrical voltage waveform produced at the output terminal may be adjusted.
References Cited (Backward Citations)
US3092824A
Cited
US3783392A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-09 | 1978-12-09 | 1979-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-09 | 1982-12-09 | 1983-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-09 | 1986-12-09 | 1987-06-10 | $7700.00 | Window Closed / Lapsed |