US3577016A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low pass active filter
Assignee: Allen Bradley Co LLC
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Filing: 1968-09-12
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Granted: 1971-05-04
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Expires: 1988-09-12
Abstract
Abstract A filter circuit for connection between a direct current power supply and a load which has incorporated in the series line running between the input and output terminals of the filter circuit a network that presents a high impedance to alternating current components that appear at either end of the filter, such network presenting relatively small resistance to direct current load currents that flow through the filter. The network shown has a transister with its emitter and collector elements connected in the filter series line, and the base element of the transistor is connected to (i) a bias resistor that has its opposite end joined through a diode with the transistor collector, and (ii) a smoothing capacitor that has its opposite side joined with the transistor emitter.
Inventors
- 👤 Hans E Weidmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:08
CPC Classifications
G; G05; G05F; G05F1/00; G05F1/10; G05F1/46; G05F1/56; H; H02; H02M; H02M1/00; H02M1/14; H02M1/15; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/12; H03H11/1213; H03H11/1217
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
109 words
In a filter circuit having a storage element at the output end thereof and a variable impedance shunting circuit at the input end thereof, the combination therewith of: a current controlling valve having load current conducting elements connected between said storage element and said variable impedance shunting circuit, said valve further including a control element; a diode; a bias resistor connected to said diode, and said resistor and diode being connected between said control element of said valve and one of said valve load current conducting elements; and a smoothing capacitor connected between said control element of said valve and the other of said valve load current conducting elements.
Claim 2
Dependent Claim
109 words
In a filter circuit having a storage element at the output end thereof and a variable impedance shunting circuit at the input end thereof, the combination therewith of: a current controlling valve having load current conducting elements connected between said storage element and said variable impedance shunting circuit, said valve further including a control element; a diode; a bias resistor connected to said diode, and said resistor and diode being connected between said control element of said valve and one of said valve load current conducting elements; and a smoothing capacitor connected between said control element of said valve and the other of said valve load current conducting elements.
Claim 3
Dependent Claim
120 words
In a filter circuit having a storage element at the output end thereof and a variable impedance shunting circuit at the input end thereof, the combination therewith of: first and second transistors with a common collector connection and the emitter of the second transistor joined to the base of the first transistor; a first resistor connected to the emitter of the first transistor, said first resistor and said first transistor connected between said storage element and said variable impedance shunting circuit; a capacitor connected across the base of said second transistor and said first resistor; and a bias resistor and a voltage establishing means connected across the base of said second transistor and the common collector connection of said transistors.
Claim 4
Dependent Claim
120 words
In a filter circuit having a storage element at the output end thereof and a variable impedance shunting circuit at the input end thereof, the combination therewith of: first and second transistors with a common collector connection and the emitter of the second transistor joined to the base of the first transistor; a first resistor connected to the emitter of the first transistor, said first resistor and said first transistor connected between said storage element and said variable impedance shunting circuit; a capacitor connected across the base of said second transistor and said first resistor; and a bias resistor and a voltage establishing means connected across the base of said second transistor and the common collector connection of said transistors.
Claim 5
Dependent Claim
71 words
In a filter circuit of the pi-type having capacitors for the shunt lines and a series line extending between the shunt lines, the combination of: a transistor with its collector and emitter inserted in the series line; a diode circuit with resistance joined across the transistor base and one of the other transistor elements; and a capacitor joined across the transistor base and the other of the emitter and collector elements.
Claim 6
Dependent Claim
71 words
In a filter circuit of the pi-type having capacitors for the shunt lines and a series line extending between the shunt lines, the combination of: a transistor with its collector and emitter inserted in the series line; a diode circuit with resistance joined across the transistor base and one of the other transistor elements; and a capacitor joined across the transistor base and the other of the emitter and collector elements.
Claim 7
Dependent Claim
61 words
In a filter circuit having a series line the combination of: a transistor having its emitter and collector in the series line; a smoothing capacitor across the transistor base and the series line; and a bias resistor and diode across the transistor base and the series line, said diode being operated in a region beyond the knee of its characteristic curve.
Claim 8
Dependent Claim
61 words
In a filter circuit having a series line the combination of: a transistor having its emitter and collector in the series line; a smoothing capacitor across the transistor base and the series line; and a bias resistor and diode across the transistor base and the series line, said diode being operated in a region beyond the knee of its characteristic curve.
Claim 9
Dependent Claim
118 words
In a filter circuit having input terminals for connection with a power supply, output terminals for connection with a load, first shunt circuit elements across the input connections, and second shunt circuit elements across the output connections, the combination therewith of: a transistor having its collector and emitter elements connected between said input and output terminals, such elements also being connected between said first and second shunt circuit elements, and said transistor also having a base element; a bias resistor connected between said base element and one of the other elements of said transistor; a diode in circuit with said bias resistor; and a smoothing capacitor connected between the base element and the remaining element of said transistor.
Claim 10
Dependent Claim
118 words
In a filter circuit having input terminals for connection with a power supply, output terminals for connection with a load, first shunt circuit elements across the input connections, and second shunt circuit elements across the output connections, the combination therewith of: a transistor having its collector and emitter elements connected between said input and output terminals, such elements also being connected between said first and second shunt circuit elements, and said transistor also having a base element; a bias resistor connected between said base element and one of the other elements of said transistor; a diode in circuit with said bias resistor; and a smoothing capacitor connected between the base element and the remaining element of said transistor.
Claim 11
Dependent Claim
130 words
In a filter circuit having input and output terminals and a series line extending between an input terminal and an output terminal, the combination of: a current controlling valve having first and second load current conducting elements connected in the series line, and also having a control element; a capacitor connected across said control element and the portion of the series line joined to said first load current conducting element; and a voltage controlling means connected across said control element and the portion of the series line joined to said second load current conducting element, such voltage controlling means having a characteristic curve with a region in which voltage change with current change is small, and being operated in such region to maintain a relatively constant voltage drop across itself.
Claim 12
Dependent Claim
130 words
In a filter circuit having input and output terminals and a series line extending between an input terminal and an output terminal, the combination of: a current controlling valve having first and second load current conducting elements connected in the series line, and also having a control element; a capacitor connected across said control element and the portion of the series line joined to said first load current conducting element; and a voltage controlling means connected across said control element and the portion of the series line joined to said second load current conducting element, such voltage controlling means having a characteristic curve with a region in which voltage change with current change is small, and being operated in such region to maintain a relatively constant voltage drop across itself.
Claim 13
Dependent Claim
28 words
A filter circuit as in claim 9 having resistance in circuit with said control element and said voltage controlling means to establish a current for said control element.
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) | 1974-05-03 | 1974-11-02 | 1975-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-03 | 1978-11-02 | 1979-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-03 | 1982-11-02 | 1983-05-04 | $7700.00 | Window Closed / Lapsed |