Patent US3774076A successfully refreshed from Google Patents.
US3774076A
Expired / Lapsed
US
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Electronic circuit breaker
Assignee: Elco Corp
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Filing: 1972-07-21
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Granted: 1973-11-20
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Expires: 1992-07-21
Abstract
Abstract An electronic circuit breaker arranged to deenergize a load when its current exceeds a first predetermined value or when its current exceeds a second (lesser) predetermined value for a predetermined interval. The circuit breaker includes an electronic switch which is in series with the load and which is arranged to remain conductive after its control electrode is energized, so long as a potential difference exists across its maintain electrodes; a pulse generator arranged to apply a series of pulses to said control electrode; a bistable switch which controls the generator; an attenuator and integrator for actuating said switch in response to either a relatively high voltage or a relatively medium-valued voltage of a predetermined duration; and means for supplying to said attenuator and integrator a voltage proportional to the load current. The foregoing circuitry is energized by a latch circuit comprising a momentary contact manual switch paralleled by a photoresistor which is responsive to a light source. The light source is energized whenever the load is energized. Thus actuation of the manual switch will turn on the pulse generator, causing the load to be energized, whereby the photoresistor will bypass the manual switch when the manual switch is released. When a short or overload current occurs, the pulse generator will be stopped, turning off the electronic switch and releasing the latch, whereby the circuit will remain off until the fault is corrected and the manual switch is reactuated.
Inventors
- 👤 R Weinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:06
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/02; H02H3/021; H02H3/08; H02H3/093
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
155 words
An electronic circuit breaker, comprising: a. a source of electrical energy, a load, and switch means having two main electrodes which are connected in a series circuit with said source and said load, said switch meAns having a control electrode and arranged to provide, upon energization of said control electrode, a substantially conductive path between said main electrodes thereof for current flow in either direction, even after said energization of said control electrode is removed, so long as a potential difference exists between said main electrodes, b. pulse generator means for energizing said control electrode with pulses having a repetition rate greater than the frequency of said alternating current source, c. current responsive means for disenabling said pulse generator means if the current in said load exceeds a predetermined value, and d. energy control means for removing supply energy to and thereby disenabling said pulse generator means if the energization of said load is interrupted.
Claim 2
Dependent Claim
155 words
An electronic circuit breaker, comprising: a. a source of electrical energy, a load, and switch means having two main electrodes which are connected in a series circuit with said source and said load, said switch meAns having a control electrode and arranged to provide, upon energization of said control electrode, a substantially conductive path between said main electrodes thereof for current flow in either direction, even after said energization of said control electrode is removed, so long as a potential difference exists between said main electrodes, b. pulse generator means for energizing said control electrode with pulses having a repetition rate greater than the frequency of said alternating current source, c. current responsive means for disenabling said pulse generator means if the current in said load exceeds a predetermined value, and d. energy control means for removing supply energy to and thereby disenabling said pulse generator means if the energization of said load is interrupted.
Claim 3
Dependent Claim
49 words
The circuit breaker of claim 1 wherein said energy control means comprises a manually operable push button switch for energizing said pulse generator means and latch means for maintaining said pulse generator means energized in response to energization of said load, even after said manually operable switch is opened.
Claim 4
Dependent Claim
52 words
The circuit breaker of claim 2 wherein said latch means for maintaining said pulse generator means energized comprises variable means, in shunt with said switch, having a normally high impedance and control means for causing the impedance of said variable means to assume a substantially lower value when said load is energized.
Claim 5
Dependent Claim
34 words
The circuit breaker of claim 2 wherein said variable means comprises a photosensitive resistor and said control means comprises a source of optical energy arranged to illuminate said resistor when said load is energized.
Claim 6
Dependent Claim
30 words
The circuit breaker of claim 1 wherein said source of electrical energy supplies alternating current, said switch means is a triac, and said pulse generator means comprises an astable multivibrator.
Claim 7
Dependent Claim
53 words
The circuit breaker of claim 1 wherein said current responsive means comprises conversion means for providing a voltage proportional to the current in said load, and switch means arranged to open a current path within, and thereby disenable, said pulse generator if the voltage provided by said conversion means exceeds a predetermined value.
Claim 8
Dependent Claim
105 words
The circuit breaker of claim 6 wherein said conversion means comprises a current-to-voltage converter, and attenuator and integrator means arranged for coupling the output of said converter to said switch means, and for (a) disenabling said pulse generator means, and hence the supply of energy to said load, relatively rapidly if the current in said load exceeds a first, relatively high predetermined value, and (b) disenabling said pulse generator means, and hence the supply of energy to said load, after an interval if the current in said load is less than said first, relatively high predetermined value, but exceeds a second, relatively lower predetermined value.
Claim 9
Dependent Claim
106 words
The circuit breaker of claim 7 wherein said attenuator and integrator means compress first and second resistors and a capacitor connected in a series path across the output of said current-to-voltage converter, said switch means being connected to a junction point between said first and second resistors, whereby said capacitor will present a relatively low impedance to any relatively rapidly rising voltage from said converter so that said first and second resistors will serve as a voltage divider, and said capacitor will charge in response to any relatively slowly rising voltage from said converter so that said first resistor and capacitor will serve as an integrator.
Claim 10
Dependent Claim
33 words
The circuit breaker of claim 7 wherein said source of electrical energy supplies alternating current and said attenuator and integrator means includes rectifier means for rectifying the output of said current responsive means.
Claim 11
Dependent Claim
36 words
The circuit breaker of claim 6 wherein said switch means comprises a bistable circuit arranged to present either a relatively low or a relatively high impedance in series with one circuit of said Pulse generator means.
Claim 12
Dependent Claim
204 words
The circuit breaker of claim 1 wherein a. said source of electrical energy supplies alternating current, said load is a projection lamp and a projector operating circuit, said switch means is a triac, b. said pulse generator means is an astable multivibrator, c. said current responsive means comprises a resistor in series with said load for providing a voltage proportional to the current through said load, an attenuator and integrator responsive to the voltage across said resistor, means for rectifying the voltage supplied to said attenuator and integrator, and a bistable switch having a normally low impedance in series with one circuit of said astable multivibrator, said bistable switch being arranged to assume a relatively high impedance, thereby to disenable said multivibrator, in response to a predetermined voltage input from said attenuator or said integrator, and, d. said energy control means comprises a manually operable push button switch paralleled by a photosensitive resistor and a source of optical energy arranged, upon energization thereof, to supply optical energy to said resistor so as to lower substantially the resistance of said resistor and thereby provide a bypass of said manually operable switch, said source of optical energy connected to be energized wherever said load is energized.
Claim 13
Dependent Claim
176 words
An electronic circuit breaker, comprising: a. a source of electrical energy, a load connected to said source, and interrupter means for disconnecting said source from said load in response to a voltage of a predetermined magnitude supplied to an input of said interrupter means, b. conversion means for providing a voltage proportional to the current supplied to said load by said source, and c. attenuator and integrator means responsive to said proportional voltage and comprising a capacitor and first and second resistors connected in a series path, said input of said interrupter means being connected to a junction point between said first and second resistors, whereby if a short occurs in said load, said proportional voltage will rise relatively rapidly, said capacitor will present a relatively low impedance to said voltage, and said first and second resistors will act as a voltage divider, and if an overload current occurs in said load, said proportional voltage will rise relatively slowly and said capacitor will charge, so that said first resistor and said capacitor will integrate said voltage.
Claim 14
Dependent Claim
176 words
An electronic circuit breaker, comprising: a. a source of electrical energy, a load connected to said source, and interrupter means for disconnecting said source from said load in response to a voltage of a predetermined magnitude supplied to an input of said interrupter means, b. conversion means for providing a voltage proportional to the current supplied to said load by said source, and c. attenuator and integrator means responsive to said proportional voltage and comprising a capacitor and first and second resistors connected in a series path, said input of said interrupter means being connected to a junction point between said first and second resistors, whereby if a short occurs in said load, said proportional voltage will rise relatively rapidly, said capacitor will present a relatively low impedance to said voltage, and said first and second resistors will act as a voltage divider, and if an overload current occurs in said load, said proportional voltage will rise relatively slowly and said capacitor will charge, so that said first resistor and said capacitor will integrate said voltage.
Claim 15
Dependent Claim
153 words
The circuit breaker of claim 12 wherein said interrupter means comprises a bistable circuit and controllable switch means for allowing current to flow from said source to said load when said bistable circuit is in a reset state and substantially preventing current flow from said source to said load when said bistable circuit is in a set state, and further including an ON switch for selectively energizing said bistable circuit, said bistable circuit including means for causing it to proceed to its reset state when energized, whereby said controllable switch means will allow said source to energize said load when said bistable switch is energized, said bistable switch arranged to be set, and thereby interrupt the supply of energy to said load, in response to a predetermined output from said integrator and attenuator means, said bistable switch being resettable only by lowering the energizing voltage for said bistable switch to a predetermined value.
References Cited (Backward Citations)
US3299322A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |