Patent US3758852A successfully refreshed from Google Patents.
US3758852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Decrease in frequency detector
Assignee: Bull HN Information Systems Italia SpA
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Filing: 1972-03-02
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Granted: 1973-09-11
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Expires: 1992-03-02
Abstract
Abstract A pair of diodes, a capacitor, a pair of resistors and a silicon unilateral switch detect a decrease in the frequency of an A.C. power source below a threshold value. When the frequency decreases below the threshold value, the detector provides a warning signal.
Inventors
- 👤 J Nowell
- 👤 L Genuit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:54
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
190 words
A decrease in frequency detector for use with an A.C. power source, said detector comprising: first and second signal-input terminals, said source being connected between said first and said second input terminals; first and second reference potentials, said second input terminal being connected to said second potential; first and second resistors; a first capacitor, said first resistor being connected between said first potential and a first plate of said first capacitor, said second potential being connected to a second plate of said first capacitor; first and second diodes each having an anode and a cathode, said anode of said first diode being connected to said first plate of said first capacitor, said second resistor being connected between said first input terminal and said cathode of said first diode, said second diode being connected between said second potential and said cathode of said first diode; a silicon unilateral switch having an anode, a cathode and a gate; and first and second output terminals, said unilateral switch being connected between said first plate of said first capacitor and said first output terminal, said second output terminal being connected to said second potential.
Claim 2
Dependent Claim
190 words
A decrease in frequency detector for use with an A.C. power source, said detector comprising: first and second signal-input terminals, said source being connected between said first and said second input terminals; first and second reference potentials, said second input terminal being connected to said second potential; first and second resistors; a first capacitor, said first resistor being connected between said first potential and a first plate of said first capacitor, said second potential being connected to a second plate of said first capacitor; first and second diodes each having an anode and a cathode, said anode of said first diode being connected to said first plate of said first capacitor, said second resistor being connected between said first input terminal and said cathode of said first diode, said second diode being connected between said second potential and said cathode of said first diode; a silicon unilateral switch having an anode, a cathode and a gate; and first and second output terminals, said unilateral switch being connected between said first plate of said first capacitor and said first output terminal, said second output terminal being connected to said second potential.
Claim 3
Dependent Claim
63 words
A decrease in frequency detector as defined in claim 1 including: a silicon controlled rectifier having an anode, a cathode and a gate, said cathode of said rectifier being connected to said second potential, said gate of said rectifier being coupled to said first output terminal; and a lamp, said lamp being connected between said first potential and said anode of said rectifier.
Claim 4
Dependent Claim
91 words
A decrease in frequency detector as defined in claim 1 including: a transformer having a primary winding and a secondary winding, said primary winding being connected between said first and said second output terminals; a silicon controlled rectifier having an anode, a cathode and a gate, said cathode of said rectifier being connected to said second potential, said secondary winding of said transformer being connected between said gate and said cathode of said rectifier; and a lamp, said lamp being connected between said first potential and said anode of said rectifier.
Claim 5
Dependent Claim
68 words
A decrease in frequency detector as defined in claim 1 including: a second capacitor; a switch, said switch being connected between a first plate of saiD second capacitor and said first plate of said first capacitor, a second plate of said second capacitor being connected to said second potential; and a rheostat, said rheostat being connected between said first potential and said first plate of said first capacitor.
Claim 6
Dependent Claim
147 words
A decrease in frequency detector as defined in claim 1 including: a transformer having a primary winding and a secondary winding, said primary winding being connected between said first and said second output terminals; a silicon controlled rectifier having an anode, a cathode and a gate, said cathode of said rectifier being connected to said second potential, said secondary winding of said transformer being connected between said gate and said cathode of said rectifier; a lamp, said lamp being connected between said first potential and said anode of said rectifier; a second capacitor; a switch, said switch being connected between a first plate of said second capacitor and said first plate of said first capacitor, a second plate of said second capacitor being connected to said second potential; and a rheostat, said rheostat being connected between said first potential and said first plate of said first capacitor.
Claim 7
Dependent Claim
119 words
A decrease in frequency detector as defined in claim 1 including: a silicon controlled rectifier having an anode, a cathode and a gate, said cathode of said rectifier being connected to said second potential, said gate of said rectifier being coupled to said first output terminal; a lamp, said lamp being connected between said first potential and said anode of said rectifier; a second capacitor; a switch, said switch being connected between a first plate of said second capacitor and said first plate of said first capacitor, a second plate of said second capacitor being connected to said second potential; and a rheostat, said rheostat being connected between said first potential and said first plate of said first capacitor.
Claim 8
Dependent Claim
238 words
A decrease in frequency detector for use with an A.C. power source, said detector comprising: first and second signal-input terminals, said source being connected between said first and said second input terminals; first and second reference potentials, said second input terminal being connected to said second potential; first and second resistors; a first capacitor, said first resistor being connected between said first potential and a first plate of said first capacitor, said second potential being connected to a second plate of said first capacitor; first and second diodes each having an anode and a cathode, said anode of said first diode being connected to said first plate of said first capacitor, said second resistor being connected between said first input terminal and said cathode of said first diode, said second diode being connected between said second potential and said cathode of said first diode; a four-layer diode having an anode and a cathode; first and second output terminals, said four-layer diode being connected between said first plate of said first capacitor and said first output terminal, said second output terminal being connected to said second potential; a silicon controlled rectifier having an anode, a cathode and a gate, said cathode of said rectifier being connected to said second potential, said gate of said rectifier being coupled to said first output terminal; and a lamp, said lamp being connected between said first potential and said anode of said rectifier.
Claim 9
Dependent Claim
238 words
A decrease in frequency detector for use with an A.C. power source, said detector comprising: first and second signal-input terminals, said source being connected between said first and said second input terminals; first and second reference potentials, said second input terminal being connected to said second potential; first and second resistors; a first capacitor, said first resistor being connected between said first potential and a first plate of said first capacitor, said second potential being connected to a second plate of said first capacitor; first and second diodes each having an anode and a cathode, said anode of said first diode being connected to said first plate of said first capacitor, said second resistor being connected between said first input terminal and said cathode of said first diode, said second diode being connected between said second potential and said cathode of said first diode; a four-layer diode having an anode and a cathode; first and second output terminals, said four-layer diode being connected between said first plate of said first capacitor and said first output terminal, said second output terminal being connected to said second potential; a silicon controlled rectifier having an anode, a cathode and a gate, said cathode of said rectifier being connected to said second potential, said gate of said rectifier being coupled to said first output terminal; and a lamp, said lamp being connected between said first potential and said anode of said rectifier.
References Cited (Backward Citations)
US3184606A
Cited
US3527965A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-10 | 1977-03-12 | 1977-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-10 | 1981-03-12 | 1981-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-10 | 1985-03-12 | 1985-09-11 | $7700.00 | Window Closed / Lapsed |