US4717869A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlled current source apparatus for signals of either polarity
Assignee: Siemens AG
•
Filing: 1986-09-02
•
Granted: 1988-01-05
•
Expires: 2006-09-02
Abstract
Abstract A controlled current source apparatus with a voltage/current converter for deriving a signal current fed to a load, includes a first current source delivering a first d-c current super-imposed on the signal current, and a second current source connected parallel to the load for delivering a second d-c current substracted from the d-c current leading into the load.
Inventors
- 👤 Rudolf Koch
- 👤 Eberhard Schmid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:27
CPC Classifications
G; G05; G05F; G05F3/00; G05F3/02; G05F1/00; G05F1/10; G05F1/46; G05F1/56; G05F1/561; H; H03; H03F; H03F3/00; H03F3/30; H03F3/3066; H03F3/34; H03F3/343; H03F3/347
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
121 words
Controlled current source apparatus for input signals of either polarity comprising at least two terminals for connection to a power source; an input terminal for receiving an input signal having signal current and signal voltage; a voltage/current converter including a resistor, a transistor and an operational amplifier with negative feedback, connected to the input terminal; an output terminal for supplying an output signal current; a load for receiving the output signal current; a first current source for supplying a first dc-current; a second current source in parallel connection with the load for supplying a second dc-current, means for summing the first dc-current with the input signal current; and means for subtracting the second dc-current from the dc-current flowing into the load.
Claim 2
Dependent Claim
121 words
Controlled current source apparatus for input signals of either polarity comprising at least two terminals for connection to a power source; an input terminal for receiving an input signal having signal current and signal voltage; a voltage/current converter including a resistor, a transistor and an operational amplifier with negative feedback, connected to the input terminal; an output terminal for supplying an output signal current; a load for receiving the output signal current; a first current source for supplying a first dc-current; a second current source in parallel connection with the load for supplying a second dc-current, means for summing the first dc-current with the input signal current; and means for subtracting the second dc-current from the dc-current flowing into the load.
Claim 3
Dependent Claim
20 words
Current source apparatus according to claim 1, wherein the first and the second d-c currents are of the same magnitude.
Claim 4
Dependent Claim
24 words
Current source apparatus according to claim 1, wherein said first and the second current sources are in the form of a current mirror device.
Claim 5
Dependent Claim
21 words
Current source apparatus according to claim 3, wherein said first and second current sources are in the form of a cascode.
Claim 6
Dependent Claim
23 words
Current source apparatus according to claim 3, wherein said first and second current sources are in the form of a Wilson current source.
Claim 7
Dependent Claim
14 words
Current source apparatus according to claim 1, wherein the load is a capacitor device.
Claim 8
Dependent Claim
15 words
Current source apparatus according to claim 1, wherein the converter is a nonlinear current/voltage converter.
References Cited (Backward Citations)
US3911353A
Cited
DE2508801A1
Cited
US4342006A
Cited
JPS5990413A
Cited
US4536662A
Cited
US4481481A
Cited
US4573177A
Cited
JPS60190011A
Cited
US4607232A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-04 | 1991-07-06 | 1992-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-04 | 1995-07-06 | 1996-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-04 | 1999-07-06 | 2000-01-05 | $7700.00 | Window Closed / Lapsed |