US3684924A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical system with energy barrier
Assignee: Westinghouse Electric Corp
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Filing: 1971-09-10
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Granted: 1972-08-15
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Expires: 1991-09-10
Abstract
Abstract An electrical system wherein an intrinsic safety barrier between electrical field apparatus and a DC supply source therefor includes voltage threshold devices connected from both lines at the field end to ground to protect against excess voltages, and current limiters in both lines between the source and field ends for preventing current above a predetermined value from flowing in the lines regardless of voltage or loading values. The current limiter in one line includes an electric valve in series in the line, which valve is turned OFF in response to loss of the aforementioned ground connection. Diodes in both lines oppose wrong polarity voltages that might be applied thereto.
Inventors
- 👤 Edward J Miller Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:28
CPC Classifications
H; H02; H02H; H02H9/00; H02H9/008
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
174 words
An electrical system comprising; A. a first set of conductors including first and second conductors for connection to a supply source; B. a second set of conductors including third and fourth conductors for connection to a load; C. ground conductor means for connection to ground; and D. protective energy barrier means interposed between the first and second sets of conductors, said energy barrier means comprising 1. first current limiting means connected between the first and third conductors for preventing currents greater tHan a predetermined value from flowing between those conductors regardless of applied voltage and loading values, 2. second current limiting means connected between the second and fourth conductors for preventing currents greater than a certain value from flowing between those conductors regardless of applied voltage and loading values, 3. first threshold voltage means connected between the third conductor and the ground conductor means for limiting voltage at said second set, and 4. second threshold voltage means connected between the fourth conductor and the ground conductor means for limiting voltage at said second set.
Claim 2
Dependent Claim
174 words
An electrical system comprising; A. a first set of conductors including first and second conductors for connection to a supply source; B. a second set of conductors including third and fourth conductors for connection to a load; C. ground conductor means for connection to ground; and D. protective energy barrier means interposed between the first and second sets of conductors, said energy barrier means comprising 1. first current limiting means connected between the first and third conductors for preventing currents greater tHan a predetermined value from flowing between those conductors regardless of applied voltage and loading values, 2. second current limiting means connected between the second and fourth conductors for preventing currents greater than a certain value from flowing between those conductors regardless of applied voltage and loading values, 3. first threshold voltage means connected between the third conductor and the ground conductor means for limiting voltage at said second set, and 4. second threshold voltage means connected between the fourth conductor and the ground conductor means for limiting voltage at said second set.
Claim 3
Dependent Claim
31 words
second current limiting means connected between the second and fourth conductors for preventing currents greater than a certain value from flowing between those conductors regardless of applied voltage and loading values,
Claim 4
Dependent Claim
31 words
second current limiting means connected between the second and fourth conductors for preventing currents greater than a certain value from flowing between those conductors regardless of applied voltage and loading values,
Claim 5
Dependent Claim
24 words
an emitter resistor connected to the emitter terminal of the transistor device and in series with the collector-emitter circuit in the load current path,
Claim 6
Dependent Claim
24 words
an emitter resistor connected to the emitter terminal of the transistor device and in series with the collector-emitter circuit in the load current path,
Claim 7
Dependent Claim
67 words
The combination as in claim 1 wherein first asymmetric current conduction means is connected between the first conductor and the first current limiter, and second asymmetric current conduction means is connected between the second conductor and the second current limiter, the forward direction of said first and second asymmetric current conduction means being in the direction of load current in the normal operating mode of the apparatus.
Claim 8
Dependent Claim
24 words
an emitter resistor connected to the emitter of the transistor device and in series with the collector-emitter circuit in the load current path, and
Claim 9
Dependent Claim
24 words
an emitter resistor connected to the emitter of the transistor device and in series with the collector-emitter circuit in the load current path, and
Claim 10
Dependent Claim
28 words
a voltage divider connected across said series combination of collector-emitter circuit and emitter resistor and having an intermediate tap connected to the base terminal of said transistor device.
Claim 11
Dependent Claim
28 words
a voltage divider connected across said series combination of collector-emitter circuit and emitter resistor and having an intermediate tap connected to the base terminal of said transistor device.
Claim 12
Dependent Claim
61 words
The combination as in claim 1 wherein one of said current limiting means includes a controllable electric valve in the path of load current, and control circuit means for the valve, said control circuit means being connected to said ground conductor means and being responsive to loss of connection between the ground conductor means and ground to turn off said valve.
Claim 13
Dependent Claim
18 words
means connected to the base terminal of the transistor device for forward biasing the base-emitter path thereof, and
Claim 14
Dependent Claim
18 words
means connected to the base terminal of the transistor device for forward biasing the base-emitter path thereof, and
Claim 15
Dependent Claim
22 words
first threshold voltage means connected between the third conductor and the ground conductor means for limiting voltage at said second set, and
Claim 16
Dependent Claim
22 words
first threshold voltage means connected between the third conductor and the ground conductor means for limiting voltage at said second set, and
Claim 17
Dependent Claim
21 words
second threshold voltage means connected between the fourth conductor and the ground conductor means for limiting voltage at said second set.
Claim 18
Dependent Claim
21 words
second threshold voltage means connected between the fourth conductor and the ground conductor means for limiting voltage at said second set.
Claim 19
Dependent Claim
15 words
diode means connected between said base terminal and the distal end of said emitter resistor.
Claim 20
Dependent Claim
15 words
diode means connected between said base terminal and the distal end of said emitter resistor.
Claim 21
Dependent Claim
67 words
The combination as in claim 3 wherein first asymmetric current conduction means is connected between the first conductor and the first current limiter, and second asymmetric current conduction means is connected between the second conductor and the second current limiter, the forward direction of said first and second asymmetric current conduction means being in the direction of load current in the normal operating mode of the apparatus.
Claim 22
Dependent Claim
29 words
The combination as in claim 1 wherein a supply source is connected to the first and second conductors, and a load is connected to the third and fourth conductors.
Claim 23
Dependent Claim
45 words
The combination as in claim 5 wherein said supply source comprises a power source and a second load, the first mentioned load comprises first translating means, said second load comprises second translating means, and one of said translating means responds to the other translating means.
Claim 24
Dependent Claim
32 words
The combination as in claim 6 wherein the first translating means comprises transmitting means responsive to a process condition, and the second translating means comprises receiving means responsive to said transmitting means.
Claim 25
Dependent Claim
32 words
The combination as in claim 6 wherein the second translating means comprises controller means and the first translating means is responsive to the second translating means and comprises process control actuating means.
Claim 26
Dependent Claim
62 words
The combination as in claim 5 wherein one of said current limiting means includes a controllable electric valve in the path of load current, and control circuit means for the valve, said control circuit means being connected to said ground control conductor means and being responsive to loss of connection between the ground conductor means and ground to turn off said valve.
Claim 27
Dependent Claim
61 words
The combination as in claim 6 wherein one of said current limiting means includes a controllable electric valve in the path of load current, and control circuit means for the valve, said control circuit means being connected to said ground conductor means and being responsive to loss of connection between the ground conductor means and ground to turn off said valve.
Claim 28
Dependent Claim
69 words
The combination as in claim 9 wherein first asymmetric current conduction means is connected between the first conductor and the first current limiting means, and second asymmetric current conduction means is connected between the second conductor and the second current limiting means, the forward direction of said first and second asymmetric current conduction means being in the direction of load current in the normal opErating mode of the apparatus.
Claim 29
Dependent Claim
69 words
The combination as in claim 10 wherein first asymmetric current conduction means is connected between the first conductor and the first current limiting means, and second asymmetric current conduction means is connected between the second conductor and the second current limiting means, the forward direction of said first and second asymmetric current conduction means being in the direction of load current in the normal operating mode of the apparatus.
Claim 30
Dependent Claim
13 words
The combination as in claim 1 wherein each said current limiting means comprises:
Claim 31
Dependent Claim
13 words
The combination as in claim 1 wherein each said current limiting means comprises:
Claim 32
Dependent Claim
21 words
The combination as in claim 14 wherein at least one of said transistor devices is a Darlington configuration compound transistor device.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |