US3935524A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement for detecting voltage differences
Assignee: Individual
•
Filing: 1973-09-26
•
Granted: 1976-01-27
•
Expires: 1993-09-26
Abstract
Abstract An electronic switching system for the control of a load, such as a motor serving to adjust the diaphragm of a motion-picture camera, comprises a normally inactive comparison circuit including a transistor bridge with a pair of NPN transistors in one pair of adjoining arms and a pair of PNP transistors in the other pair. Two complementary transistors in each half of the bridge, lying between diagonally opposite corners, are provided with a common biasing circuit shunted across that bridge diagonal, the load being connected across the other bridge diagonal. Each biasing circuit includes a resistive voltage divider with taps joined to the bases of the associated bridge transistors and a group of cascaded ancillary transistors connected across a section of the voltage divider containing one of these taps. The first ancillary transistor of each cascaded group has its base connected to an associated input terminal receiving a switching signal and a reference voltage, respectively. A differential amplifier, connected across the input terminals, emits an unbalance signal which applies power to a pair of normally open-circuited ancillary transistors, forming part of the two cascaded groups to activate the comparison circuit by energizing the emitters of these ancillary transistors via a switching stage including a constant-current source.
Inventors
- 👤 Heinrich Cap
- 👤 Herbert Krammer
- 👤 Robert Scheiber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:19
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/085; G05; G05D; G05D3/00; G05D3/12; G05D3/14; G05D3/1472
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
134 words
A circuit arrangement for detecting deviations of the setting of an adjustable camera diaphragm from a preselected value, comprising: a differential amplifier provided with a first input connected to a source of reference voltage and with a second input connected to an output of a photoelectric transducer juxtaposed with the diaphragm for illumination therethrough, said differential amplifier further having rectifying output means generating an unbalance signal of predetermined polarity in the presence of a difference of either polarity between said reference voltage and an output voltage of said transducer; a normally inactive comparison circuit connected across said first and second inputs and provided with an activating lead; and switching means connected between said output means and said activating lead for placing said comparison circuit in an operative condition in response to said unbalance signal.
Claim 2
Dependent Claim
134 words
A circuit arrangement for detecting deviations of the setting of an adjustable camera diaphragm from a preselected value, comprising: a differential amplifier provided with a first input connected to a source of reference voltage and with a second input connected to an output of a photoelectric transducer juxtaposed with the diaphragm for illumination therethrough, said differential amplifier further having rectifying output means generating an unbalance signal of predetermined polarity in the presence of a difference of either polarity between said reference voltage and an output voltage of said transducer; a normally inactive comparison circuit connected across said first and second inputs and provided with an activating lead; and switching means connected between said output means and said activating lead for placing said comparison circuit in an operative condition in response to said unbalance signal.
Claim 3
Dependent Claim
151 words
A circuit arrangement as defined in claim 1 wherein said comparison circuit comprises a transistor bridge including a first pair of complementary bridge transistors and a second pair of complementary bridge transistors on opposite sides of an input diagonal, a first anda second resistive voltage divider respectively associated with said first and second pairs of bridge transistors and connected across a direct-current power supply in parallel with said input diagonal, each pair of bridge transistors having bases connected to separate taps on the associated voltage divider for biasing thereby, and first and second ancillary transistor means respectively connected across sections of said first and second voltage dividers including one of said taps thereof, said first and second ancillary transistor means having control electrodes respectively connected to said first and second inputs and having other electrodes connected to said activating lead, said bridge further having an output diagonal connected across a load.
Claim 4
Dependent Claim
45 words
A circuit arrangement as defined in claim 2 wherein said bridge transistors include two PNP transistors in two adjacent bridge arms on one side of said output diagonal and two NPN transistors in two adjacent bridge arms on the other side of said output diagonal.
Claim 5
Dependent Claim
32 words
A circuit arrangement as defined in claim 3 wherein the taps of said sections of said voltage dividers are symmetrically connected to the bases of two bridge transistors of like conductivity type.
Claim 6
Dependent Claim
38 words
A circuit arrangement as defined in claim 2 wherein each of said ancillary transistor means comprises a group of cascaded transistors, said activating lead being a common emitter circuit for an ancillary transistor from each of said groups.
Claim 7
Dependent Claim
25 words
A circuit arrangement as defined in claim 5 wherein said switching means comprises a Schmitt trigger with an output stage in said common emitter circuit.
Claim 8
Dependent Claim
16 words
A circuit arrangement as defined in claim 2 wherein said switching means comprises a constant-current source.
Claim 9
Dependent Claim
56 words
A circuit arrangement as defined in claim 7 wherein said constant-current source comprises a pair of homopolar series transistors connected across said power supply and provided with bases connected to respective sources of fixed biasing potential, and a resistor inserted between an emitter of one of said series transistors and a terminal of said power supply.
Claim 10
Dependent Claim
111 words
A circuit arrangement for detecting the existence of voltage differences between two signals, comprising: a differential amplifier provided with a first and a second input connected to a pair of voltage sources for receiving respective signal voltages therefrom, said differential amplifier further having rectifying output means generating an unbalance signal of predetermined polarity in the presence of a difference of either polarity between said signal voltages; a normally inactive comparison circuit connected across said first and second inputs and provided with an activating lead; and switching means connected between said output means and said activating lead for placing said comparison circuit in an operative condition in response to said unbalance signal.
Claim 11
Dependent Claim
111 words
A circuit arrangement for detecting the existence of voltage differences between two signals, comprising: a differential amplifier provided with a first and a second input connected to a pair of voltage sources for receiving respective signal voltages therefrom, said differential amplifier further having rectifying output means generating an unbalance signal of predetermined polarity in the presence of a difference of either polarity between said signal voltages; a normally inactive comparison circuit connected across said first and second inputs and provided with an activating lead; and switching means connected between said output means and said activating lead for placing said comparison circuit in an operative condition in response to said unbalance signal.
Claim 12
Dependent Claim
152 words
A circuit arrangement as defined in claim 9 wherien said comparison circuit comprises a transistor bridge including a first pair of complementary bridge transistors and a second pair of complementary bridge transistors on opposite sides of an input diagonal, a first and a second resistive voltage divider respectively associated with said first and second pairs of bridge transistors and connected across a direct-current power supply in parallel with said input diagonal, each pair of bridge transistors having bases connected to separate taps on the associated voltage divider for biasing thereby, and first and second ancillary transistor means respectively connected across sections of said first and second voltage dividers including one of said taps thereof, said first and second ancillary transistor means having control electrodes respectively connected to said first and second inputs and having other electrodes connected to said activating lead, said bridge further having an output diagonal connected across a load.
Claim 13
Dependent Claim
45 words
A circuit arrangement as defined in claim 10 wherein said bridge transistors include two PNP transistors in two adjacent bridge arms on one side of said output diagonal and two NPN transistors in two adjacent bridge arms on the other side of said output diagonal.
Claim 14
Dependent Claim
32 words
A circuit arrangement as defined in claim 11 wherein the taps of said sections of said voltage dividers are symmetrically connected to the bases of two bridge transistors of like conductivity type.
Claim 15
Dependent Claim
38 words
A circuit arrangement as defined in claim 10 wherein each of said ancillary transistor means comprises a group of cascaded transistors, said activating lead being a common emitter circuit for an ancillary transistor from each of said groups.
Claim 16
Dependent Claim
25 words
A circuit arrangement as defined in claim 13 wherein said switching means comprises a Schmitt trigger with an output stage in said common emitter circuit.
Claim 17
Dependent Claim
16 words
A circuit arrangement as defined in claim 10 wherein said switching means comprises a constant-current source.
Claim 18
Dependent Claim
56 words
A circuit arrangement as defined in claim 15 wherein said constant-current source comprises a pair of homopolar series transistors connected across said power supply and provided with bases connected to respective sources of fixed biasing potential, and a resistor inserted between an emitter of one of said series transistors and a terminal of said power supply.
References Cited (Backward Citations)
US3365587A
Cited
DE1438232A1
Cited
US3317901A
Cited
US3386081A
Cited
US3278761A
Cited
JPS4425303Y1
Cited
US3475622A
Cited
US3539830A
Cited
US3538444A
Cited
US3567967A
Cited
US3573495A
Cited
US3523228A
Cited
US3747487A
Cited
US3611894A
Cited
US3704656A
Cited
US3602799A
Cited
US3727107A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-26 | 1979-07-28 | 1980-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-26 | 1983-07-28 | 1984-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-26 | 1987-07-28 | 1988-01-27 | $7700.00 | Window Closed / Lapsed |