US4011555A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio and television alarm system
Assignee: MARKOWITZ MONTE
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Filing: 1974-08-20
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Granted: 1977-03-08
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Expires: 1994-08-20
Abstract
Abstract An alarm system which is particularly adapted for use in connection with an appliance, the system sensing the removal of the power supply plug from the convenience outlet to trigger an audio alarm. The system includes a one hertz oscillator circuit which feeds a one hertz signal to a one kilohertz oscillator signal including an input gate circuit, the output of the one kilohertz oscillator circuit feeding an output transformer connected to the audio signaling device upon triggering of the one kilohertz oscillator circuit. The system further includes a gating device, in the form of a controlled rectifier, the gate and cathode electrodes of which are connected to a source of alternating current supplied through the plug and convenience outlet assembly whereby the controlled rectifier is triggered to the conductive state to permit conduction of a multiple frequency signal through the output transformer and gate circuit upon removal of the power supply plug from the convenience outlet. There is provided a reset circuit including a reset switch which shunts the controlled rectifier, the reset switch being actuated from a position external to the appliance cabinet.
Inventors
- 👤 Jack L. Pearce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:13
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/02; G08B13/14; G08B13/1409
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
257 words
An alarm system for a portable appliance which appliance is energized from a fixed source of alternating current potential by an electrical cord having two conductors adapted to conduct the a-c potential from the fixed source to the appliance comprising first oscillator circuit means for providing output gating pulses at a first preselected audio frequency, second oscillator circuit means electrically connected with said first oscillator means for providing an output signal at a second preselected audio frequency higher than said first audio frequency, output means electrically connected with said second oscillator means for providing a audible audio output alarm in response to said second output signal when in an enabled condition and providing no audio output when in a disabled condition, said second oscillator circuit means providing a pair of distinct audio frequency signals to said output means, said output means comprising solid state switching means having a first condition disabling said output means and a second condition enabling said output means, electrical circuit means connecting said solid state switching means to the two conductors utilized to conduct electrical energy from the fixed source to the appliance, said solid state switching means being operable independently of said first oscillator means and being in said first condition in response to the a-c potential being at the two conductors and being in said second condition in response to the a-c potential being absent at the two conductors whereby said audio output alarm will be sounded when the two conductors are removed from the a-c potential at the fixed source.
Claim 2
Dependent Claim
257 words
An alarm system for a portable appliance which appliance is energized from a fixed source of alternating current potential by an electrical cord having two conductors adapted to conduct the a-c potential from the fixed source to the appliance comprising first oscillator circuit means for providing output gating pulses at a first preselected audio frequency, second oscillator circuit means electrically connected with said first oscillator means for providing an output signal at a second preselected audio frequency higher than said first audio frequency, output means electrically connected with said second oscillator means for providing a audible audio output alarm in response to said second output signal when in an enabled condition and providing no audio output when in a disabled condition, said second oscillator circuit means providing a pair of distinct audio frequency signals to said output means, said output means comprising solid state switching means having a first condition disabling said output means and a second condition enabling said output means, electrical circuit means connecting said solid state switching means to the two conductors utilized to conduct electrical energy from the fixed source to the appliance, said solid state switching means being operable independently of said first oscillator means and being in said first condition in response to the a-c potential being at the two conductors and being in said second condition in response to the a-c potential being absent at the two conductors whereby said audio output alarm will be sounded when the two conductors are removed from the a-c potential at the fixed source.
Claim 3
Dependent Claim
81 words
The improvement of claim 1 further including reset circuit means and actuating means for said reset circuit means, said solid state switching means including gate controller means operable for placing said solid state switching means in said second condition in response to a-c potential being absent at the two conductors, said reset circuits means resetting said solid state switching means to said first condition upon returning the source of electrical energy to the two conductors and operation of said actuating means.
Claim 4
Dependent Claim
44 words
The improvement of claim 2 with the appliance having an enclosure and wherein said reset circuit means is mounted within the enclosure of the appliance and said actuating means is operated outside of the enclosure, said output including a speaker mounted in the enclosure.
Claim 5
Dependent Claim
71 words
The improvement of claim 3 wherein said output means includes a transformer connected to said speaker, said solid state switching means including a three terminal semi-conductor device having a controlled electrode and having a pair of principal electrodes with said pair of principal electrode being connected in series circuit with said transformer, said solid state switching means being held down by the presence of the electrical energy at the two conductors.
Claim 6
Dependent Claim
63 words
The improvement of claim 4 wherein said gate controller means includes a two terminal semi-conductor device, said source of electrical energy being connected to said controlled electrode of said three terminal semi-conductor device, said reset circuit means is connected in shunt relation with said three terminal semi-conductor device, the operation of said actuating means causing said three terminal semi-conductor device to become nonconductive.
Claim 7
Dependent Claim
52 words
The improvement of claim 5 wherein said resetting means is a reed switch and said three terminal semi-conductor device is a controlled rectifier, said controlled rectifier being rendered nonconductive in response to the closure of said reed switch by said actuating means, said actuating means being nonconductively coupled to said reed switch.
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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) | 1980-03-07 | 1980-09-06 | 1981-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-07 | 1984-09-06 | 1985-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-07 | 1988-09-06 | 1989-03-08 | $7700.00 | Window Closed / Lapsed |