Patent US3879672A successfully refreshed from Google Patents.
US3879672A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital automatic gain control circuit
Assignee: Bull HN Information Systems Italia SpA
•
Filing: 1973-09-04
•
Granted: 1975-04-22
•
Expires: 1993-09-04
Abstract
Abstract A plurality of threshold detectors, flip-flops and a pulse-toanalog converter develop a voltage which can provide rapid changes in the gain of a variable gain amplifier to keep the level of the output signals from the amplifier nearly constant even when the amplitude of the digital input signals changes suddenly.
Inventors
- 👤 Eddy J Milanes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:23
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
274 words
A digital automatic gain control circuit for use with a source of signals, said circuit comprising: a variable gain amplifier having first and second input leads and an output lead, the gain of said amplifier being determined by the amplitude of voltage applied to said second input lead, said first input lead of said amplifier being coupled to said source of signals; a peak detector having an input lead and an output lead, said input lead of said peak detector being coupled to said output lead of said amplifier; a first threshold detector having an input lead and an output lead, said input lead of said first threshold detector being coupled to said output lead of said amplifier, the amplitude of voltage from said threshold detector being determined by the amplitude of a signal from said amplifier; a first flip-flop having first, second and third input leads and an output lead, said first and said third input leads of said first flip-flop being connected to said output lead of said first threshold detector, said second input lead of said first flip-flop being connected to said output lead of said peak detector, the voltage from said output lead of said flip-flop being determined by the amplitude of voltage applied to said first and said third input leads of said first flip-flop; and a summing circuit, said summing circuit being connected between said output lead of said first flip-flop and said second input lead of said amplifier, the voltage which said summing circuit provides to said second input lead of said amplifier being determined by the value of voltage from the output lead of said flip-flop.
Claim 2
Dependent Claim
274 words
A digital automatic gain control circuit for use with a source of signals, said circuit comprising: a variable gain amplifier having first and second input leads and an output lead, the gain of said amplifier being determined by the amplitude of voltage applied to said second input lead, said first input lead of said amplifier being coupled to said source of signals; a peak detector having an input lead and an output lead, said input lead of said peak detector being coupled to said output lead of said amplifier; a first threshold detector having an input lead and an output lead, said input lead of said first threshold detector being coupled to said output lead of said amplifier, the amplitude of voltage from said threshold detector being determined by the amplitude of a signal from said amplifier; a first flip-flop having first, second and third input leads and an output lead, said first and said third input leads of said first flip-flop being connected to said output lead of said first threshold detector, said second input lead of said first flip-flop being connected to said output lead of said peak detector, the voltage from said output lead of said flip-flop being determined by the amplitude of voltage applied to said first and said third input leads of said first flip-flop; and a summing circuit, said summing circuit being connected between said output lead of said first flip-flop and said second input lead of said amplifier, the voltage which said summing circuit provides to said second input lead of said amplifier being determined by the value of voltage from the output lead of said flip-flop.
Claim 3
Dependent Claim
274 words
A digital automatic gain control circuit for use with a source of signals, said circuit comprising: a variable gain amplifier having first and second input leads and an output lead, the gain of said amplifier being determined by the amplitude of voltage applied to said second input lead, said first input lead of said amplifier being coupled to said source of signals; a peak detector having an input lead and an output lead, said input lead of said peak detector being coupled to said output lead of said amplifier; a first threshold detector having an input lead and an output lead, said input lead of said first threshold detector being coupled to said output lead of said amplifier, the amplitude of voltage from said threshold detector being determined by the amplitude of a signal from said amplifier; a first flip-flop having first, second and third input leads and an output lead, said first and said third input leads of said first flip-flop being connected to said output lead of said first threshold detector, said second input lead of said first flip-flop being connected to said output lead of said peak detector, the voltage from said output lead of said flip-flop being determined by the amplitude of voltage applied to said first and said third input leads of said first flip-flop; and a summing circuit, said summing circuit being connected between said output lead of said first flip-flop and said second input lead of said amplifier, the voltage which said summing circuit provides to said second input lead of said amplifier being determined by the value of voltage from the output lead of said flip-flop.
Claim 4
Dependent Claim
274 words
A digital automatic gain control circuit for use with a source of signals, said circuit comprising: a variable gain amplifier having first and second input leads and an output lead, the gain of said amplifier being determined by the amplitude of voltage applied to said second input lead, said first input lead of said amplifier being coupled to said source of signals; a peak detector having an input lead and an output lead, said input lead of said peak detector being coupled to said output lead of said amplifier; a first threshold detector having an input lead and an output lead, said input lead of said first threshold detector being coupled to said output lead of said amplifier, the amplitude of voltage from said threshold detector being determined by the amplitude of a signal from said amplifier; a first flip-flop having first, second and third input leads and an output lead, said first and said third input leads of said first flip-flop being connected to said output lead of said first threshold detector, said second input lead of said first flip-flop being connected to said output lead of said peak detector, the voltage from said output lead of said flip-flop being determined by the amplitude of voltage applied to said first and said third input leads of said first flip-flop; and a summing circuit, said summing circuit being connected between said output lead of said first flip-flop and said second input lead of said amplifier, the voltage which said summing circuit provides to said second input lead of said amplifier being determined by the value of voltage from the output lead of said flip-flop.
Claim 5
Dependent Claim
109 words
A digital automatic gain control circuit as defined in claim 1 including: a second threshold detector having an input lead and an output lead, said input lead of said second threshold detector being coupled to said output lead of said amplifier; and a second flip-flop having first, second and third input leads and an output lead, said first and said third input leads of said second flip-flop being connected to said output lead of said second threshold detector, said second input lead of said second flip-flop being connected to said output lead of said peak detector, said output lead of said second flip-flop being coupled to said summing circuit.
Claim 6
Dependent Claim
331 words
A digital automatic gains control circuit for use with a source of signals, said circuit comprising: a variable gain amplifier and first and second input leads and an output lead, said first input lead of said amplifier being coupled to said source of signals the gain of said amplifier being determined by the amplitude of voltage applied to said second input lead; a phase shift circuit having an input lead and an output lead, said input lead of said phase circuit being coupled to said output lead of said amplifier; a zero crossing detector having an input lead and an output lead, said input lead of said zero crossing detector being connected to said output lead of said phase shift circuit; a differentiator having an input lead and an output lead, said input lead of said differentiator being coupled to said output lead of said zero crossing detector; a first threshold detector having an input lead and an output lead, said input lead of said threshold detector being coupled to said output lead of said amplifier, the amplitude of voltage from said threshold detector being determined by the amplitude of a signal from said amplifier; a first threshold detector having first, second and third input leads and an output lead, said first and said third input leads of said flip-flop being connected to said output lead of said first threshold detector, said second input lead of said first flip-flop being coupled to said output lead of said differentiator, the voltage from said output lead of said flip-flop being determined by the amplitude of voltage applied to said first and said third input leads of said first flip-flop; and a summing circuit, said summing circuit being connected between said output lead of said first flip-flop and said second input lead of said amplifier, the voltage which said summing circuit provides to said second input lead of said amplifier being determined by the value of voltage from the output lead of said flip-flop.
Claim 7
Dependent Claim
331 words
A digital automatic gains control circuit for use with a source of signals, said circuit comprising: a variable gain amplifier and first and second input leads and an output lead, said first input lead of said amplifier being coupled to said source of signals the gain of said amplifier being determined by the amplitude of voltage applied to said second input lead; a phase shift circuit having an input lead and an output lead, said input lead of said phase circuit being coupled to said output lead of said amplifier; a zero crossing detector having an input lead and an output lead, said input lead of said zero crossing detector being connected to said output lead of said phase shift circuit; a differentiator having an input lead and an output lead, said input lead of said differentiator being coupled to said output lead of said zero crossing detector; a first threshold detector having an input lead and an output lead, said input lead of said threshold detector being coupled to said output lead of said amplifier, the amplitude of voltage from said threshold detector being determined by the amplitude of a signal from said amplifier; a first threshold detector having first, second and third input leads and an output lead, said first and said third input leads of said flip-flop being connected to said output lead of said first threshold detector, said second input lead of said first flip-flop being coupled to said output lead of said differentiator, the voltage from said output lead of said flip-flop being determined by the amplitude of voltage applied to said first and said third input leads of said first flip-flop; and a summing circuit, said summing circuit being connected between said output lead of said first flip-flop and said second input lead of said amplifier, the voltage which said summing circuit provides to said second input lead of said amplifier being determined by the value of voltage from the output lead of said flip-flop.
Claim 8
Dependent Claim
56 words
A digital automatic gain control circuit as defined in claim 3 including: an open collector inverter having an input lead and an output lead, said input lead of said inverter being connected to said output lead of said differentiator, said output lead of said inverter being connected to said second input lead of said first flip-flop.
Claim 9
Dependent Claim
108 words
A digital automatic gain control circuit as defined in claim 3, including: a second threshold detector having an input lead and an output lead, said input lead of said second threshold detector being coupled to said output lead of said amplifier; and a second flip-flop having first, second and third input leads and an output lead, said first and said third input leads of said second flip-flop being connected to said output lead of said second threshold detector, said second input lead of said second flip-flop being coupled to said output lead of said differentiator, said output lead of said second flip-flop being coupled to said summing circuit.
References Cited (Backward Citations)
US3206689A
Cited
US3339018A
Cited
US3684968A
Cited
US3758868A
Cited
US3764923A
Cited
US3783385A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |