US3652913A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system including common mode feedback
Assignee: Individual
•
Filing: 1970-07-01
•
Granted: 1972-03-28
•
Expires: 1990-07-01
Abstract
Abstract In a differentially operating control system a common mode feedback circuit is described which provides automatic compensation of the quiescent operating point despite variations in component values and semiconductor parameters. The circuit is illustrated in a control system for differentially operating a load, such as a DC motor, in accordance with the difference between a pair of input signals to accurately position the shaft of the motor in respect of such difference.
Inventors
- 👤 Robert D Leland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:27
CPC Classifications
G; G05; G05D; G05D3/00; G05D3/12; G05D3/14; G05D3/1472; G05D1/00; G05D1/02; G05D1/0206
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
135 words
A control system for differentially operating a load in accordance with the difference between a pair of input signals comprising, in combination: a differential amplifier responsive to the pair of input signals and having a common mode input circuit and a pair of output circuits providing a pair of differential output signals, a pair of power amplifiers each direct-coupled between one of said output circuits and one side of the load to be controlled to operate the load in accordance with the algebraic sum of the output signals of the differential amplifier, and means connected to the power amplifiers to provide a common mode operating point therefor and connected to the common mode input circuit of the differential amplifier to provide a negative feedback therebetween to attenuate the common mode gain of the power amplifiers.
Claim 2
Dependent Claim
135 words
A control system for differentially operating a load in accordance with the difference between a pair of input signals comprising, in combination: a differential amplifier responsive to the pair of input signals and having a common mode input circuit and a pair of output circuits providing a pair of differential output signals, a pair of power amplifiers each direct-coupled between one of said output circuits and one side of the load to be controlled to operate the load in accordance with the algebraic sum of the output signals of the differential amplifier, and means connected to the power amplifiers to provide a common mode operating point therefor and connected to the common mode input circuit of the differential amplifier to provide a negative feedback therebetween to attenuate the common mode gain of the power amplifiers.
Claim 3
Dependent Claim
30 words
The invention of claim 1 characterized in that said means for providing a common mode operating point comprises a resistor adding network connected across the outputs of the power amplifiers.
Claim 4
Dependent Claim
15 words
The invention defined in claim 1 characterized in that said amplifiers provide direct current amplification.
Claim 5
Dependent Claim
22 words
The invention as defined in claim 1 characterized in that a load is included in and is a part of the circuit.
Claim 6
Dependent Claim
16 words
The invention defined by claim 4 characterized in that said load is an electro-mechanical energy converter.
Claim 7
Dependent Claim
23 words
The invention defined by claim 2 characterized in that an electro-mechanical energy convertor is included in and is a part of the circuit.
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) | 1975-03-28 | 1975-09-27 | 1976-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-28 | 1979-09-27 | 1980-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-28 | 1983-09-27 | 1984-03-28 | $7700.00 | Window Closed / Lapsed |