US4068279A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power monitor
Assignee: BANK OF STAR CITY
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Filing: 1976-10-28
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Granted: 1978-01-10
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Expires: 1996-10-28
Abstract
Abstract Electrical power lines connected to loads are monitored by a protective circuit assembly to suppress peak transient voltages and surges by use of a Zener clamping device. Impedance branches connected in parallel with the Zener device share the transient loads when Zener break-down occurs under abnormal conditions. Each impedance branch includes a non-linear resistor arranged to clip voltages at different levels, at least one of the branches having a fixed resistor connected in series with the non-linear resistor.
Inventors
- 👤 Gerald J. Byrnes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:58
CPC Classifications
H; H02; H02H; H02H9/00; H02H9/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
158 words
A current shunting protection circuit connected to a source of line voltage including a plurality of parallel connected branches, voltage clamping means in a first of said branches for conducting current therethrough in response to line voltage exceeding a predetermined voltage breakdown value, non-linear impedance devices respectively connected in each of the other of the branches for establishing shunt paths therein under transient voltage conditions to clip peak voltages at different levels, and fixed impedance means connected in series with at least one of said non-linear impedance devices in a second of the branches for developing a volt drop across said second of the branches under normal peak voltage conditions that is less than said voltage breakdown value of the clamping means to prevent conduction of current therethrough, said non-linear impedance devices having impedances which decrease sharply when the line voltage exceeds said predetermined voltage breakdown value to share transient loads amongst said branches under transient voltage conditions.
Claim 2
Dependent Claim
158 words
A current shunting protection circuit connected to a source of line voltage including a plurality of parallel connected branches, voltage clamping means in a first of said branches for conducting current therethrough in response to line voltage exceeding a predetermined voltage breakdown value, non-linear impedance devices respectively connected in each of the other of the branches for establishing shunt paths therein under transient voltage conditions to clip peak voltages at different levels, and fixed impedance means connected in series with at least one of said non-linear impedance devices in a second of the branches for developing a volt drop across said second of the branches under normal peak voltage conditions that is less than said voltage breakdown value of the clamping means to prevent conduction of current therethrough, said non-linear impedance devices having impedances which decrease sharply when the line voltage exceeds said predetermined voltage breakdown value to share transient loads amongst said branches under transient voltage conditions.
Claim 3
Dependent Claim
70 words
The combination of claim 1, wherein another of said non-linear impedance devices establishes a clipping level above that of the voltage clamping means, said one of the non-linear impedance devices in series with the fixed impedance means establishing a clipping level for the second of the branches which is above that of the voltage clamping means but less than the clipping level of said other of the non-linear impedance devices.
Claim 4
Dependent Claim
35 words
The combination of claim 2, wherein said voltage clamping means is a Zener device and said non-linear impedance devices are varistors having voltage ratings above and below the voltage breakdown value of the Zener device.
Claim 5
Dependent Claim
31 words
The combination of claim 3, wherein said line voltage has a sinusoidal waveform with a normal peak voltage value approximately equal to the breakdown voltage value of the voltage clamping means.
Claim 6
Dependent Claim
35 words
The combination of claim 1, wherein said voltage clamping means is a Zener device and said non-linear impedance devices are varistors having voltage ratings above and below the voltage breakdown value of the Zener device.
Claim 7
Dependent Claim
31 words
The combination of claim 5, wherein said line voltage has a sinusoidal waveform with a normal peak voltage value approximately equal to the voltage breakdown value of the voltage clamping means.
Claim 8
Dependent Claim
31 words
The combination of claim 1, wherein said line voltage has a sinusoidal waveform with a normal peak voltage value approximately equal to the voltage breakdown value of the voltage clamping means.
Claim 9
Dependent Claim
70 words
The combination of claim 7, wherein another of said non-linear impedance devices establishes a clipping level above that of the voltage clamping means, said one of the non-linear impedance devices in series with the fixed impedance means establishing a clipping level for the second of the branches which is above that of the voltage clamping means but less than the clipping level of said other of the non-linear impedance devices.
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) | 1981-01-09 | 1981-07-11 | 1982-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-09 | 1985-07-11 | 1986-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-09 | 1989-07-11 | 1990-01-10 | $7700.00 | Window Closed / Lapsed |