US4234904A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and device for the protection of electrical energy supply systems controlled by means of audio-frequency
Assignee: Siemens Building Technologies AG
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Filing: 1979-07-18
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Granted: 1980-11-18
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Expires: 1999-07-18
Abstract
Abstract A process for the protection of electrical systems upon return of power after power interruptions, through the immediate disconnection of secondary consuming units by an audio-frequency control receiver, and the subsequent reconnection thereof in timed sequence. The audio-frequency control receivers have, in addition to a normal control path, a second path, through which, upon return of the voltage, the switch relay for secondary consuming units is disconnected upon reaching 2/3 of the system voltage. The process may be implemented through the use of a two-state D.C. relay, which is controlled by a secondary path including a cold lead to the system voltage. The process may alternatively be implemented through the use of a two-state A.C. relay which is controlled through a half-wave secondary path including a capacitor/resistor parallel circuit.
Inventors
- 👤 Kjell T. Fahlesson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:49
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/02; H02H3/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
83 words
A process for the protection of electrical energy supply systems by means of audio-frequency signals upon the return of voltage after interruptions of the voltage, wherein the consuming units with secondary priorities upon return of the system voltage, are cut off automatically at a threshold which is a maximum of 2/3 of the system voltage through the audio-frequency control receiver, and that these consuming units are reconnected in a time sequence order after assured reconstruction of the energy supply by audio-frequency control signals.
Claim 2
Dependent Claim
83 words
A process for the protection of electrical energy supply systems by means of audio-frequency signals upon the return of voltage after interruptions of the voltage, wherein the consuming units with secondary priorities upon return of the system voltage, are cut off automatically at a threshold which is a maximum of 2/3 of the system voltage through the audio-frequency control receiver, and that these consuming units are reconnected in a time sequence order after assured reconstruction of the energy supply by audio-frequency control signals.
Claim 3
Dependent Claim
90 words
Apparatus for protecting electrical energy supply systems wherein supply to secondary loads is normally controlled by means of audio-frequency signals, said apparatus comprising a two-state switching relay, a normal control path coupled to said relay for controlling the state of said switching relay under normal conditions to control the secondary loads, and an additional control path coupled to said relay to momentarily energize said relay in a direction which momentarily assures disconnection of the secondary loads, prior to reaching 2/3 maximum supply voltage following interruption of the electrical energy supply.
Claim 4
Dependent Claim
90 words
Apparatus for protecting electrical energy supply systems wherein supply to secondary loads is normally controlled by means of audio-frequency signals, said apparatus comprising a two-state switching relay, a normal control path coupled to said relay for controlling the state of said switching relay under normal conditions to control the secondary loads, and an additional control path coupled to said relay to momentarily energize said relay in a direction which momentarily assures disconnection of the secondary loads, prior to reaching 2/3 maximum supply voltage following interruption of the electrical energy supply.
Claim 5
Dependent Claim
49 words
Apparatus according to claim 2 wherein said two-state switching relay is a D.C. relay, and wherein said additional path includes a second relay and a cold lead, through the switch contacts of said second relay, and operation of said second relay being controlled by means of said cold lead.
Claim 6
Dependent Claim
22 words
The apparatus of claim 2 wherein said two-state switching relay is an A.C. relay operated through a half-wave of the system voltage.
Claim 7
Dependent Claim
38 words
The apparatus of claim 4 wherein said additional control path includes a parallel circuit including a capacitator, a series diode, and a resistor, said additional control circuit being connected between said A.C. relay and a system supply terminal.
Claim 8
Dependent Claim
32 words
The apparatus of claim 5, wherein said capacitator and said resistor are selected so that the frequency of the switching of said switching relay is several times less than the system frequency.
Claim 9
Dependent Claim
31 words
The apparatus according to claim 2, wherein time constants of said additional control path are so selected that an interruption of the system of less than 30 seconds has no effect.
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) | 1983-11-18 | 1984-05-19 | 1984-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-18 | 1988-05-19 | 1988-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-18 | 1992-05-19 | 1992-11-18 | $7700.00 | Window Closed / Lapsed |