Patent US3758855A successfully refreshed from Google Patents.
US3758855A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resistance controllable indicator
Assignee: Individual
•
Filing: 1970-07-09
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Granted: 1973-09-11
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Expires: 1990-07-09
Abstract
Abstract A resistance controllable indicator involving a frequency generating circuit wherein the frequency is a function of resistance, the circuit including a pair of spaced terminals normally defining infinite resistance between them and across which, the resistance may be altered on the occasion of and in response to certain phenomena to be indicated and which involve changes in electrical resistance conductivity. No on-off switch is necessary to preserve battery power during periods when not in use.
Inventors
- 👤 R Meyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:03
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
187 words
A resistance controllable indicator comprising a transistorized frequency generating circuit whose frequency is determined by resistance and reactance, said frequency generating circuit including a transistor of the silicon type having base, emitter and collector electrodes and characterized by having low leakage, a power source and indicator, means connecting said emitter and collector electrodes in circuit with said power source and indicator, a second transistor and circuit in signal supply relationship to the base electrode of said first transistor, said second transistor being also of the silicon type having base, emitter and collector electrodes and characterized by low leakage, means for feeding back from said indicator circuit, to said second transistor, signal energy appearing in said indicator circuit, said second transistor circuit comprising a normally open circuit defined by a pair of spaced contacts determining substantially infinite resistance whereby to provide a standby condition with negligible battery drain and without the use of an on/off switch, and means for connecting a lower order of resistance across said spaced contacts to draw sufficient current to produce a response from said indicator in accordance with said lower order of resistance.
Claim 2
Dependent Claim
187 words
A resistance controllable indicator comprising a transistorized frequency generating circuit whose frequency is determined by resistance and reactance, said frequency generating circuit including a transistor of the silicon type having base, emitter and collector electrodes and characterized by having low leakage, a power source and indicator, means connecting said emitter and collector electrodes in circuit with said power source and indicator, a second transistor and circuit in signal supply relationship to the base electrode of said first transistor, said second transistor being also of the silicon type having base, emitter and collector electrodes and characterized by low leakage, means for feeding back from said indicator circuit, to said second transistor, signal energy appearing in said indicator circuit, said second transistor circuit comprising a normally open circuit defined by a pair of spaced contacts determining substantially infinite resistance whereby to provide a standby condition with negligible battery drain and without the use of an on/off switch, and means for connecting a lower order of resistance across said spaced contacts to draw sufficient current to produce a response from said indicator in accordance with said lower order of resistance.
Claim 3
Dependent Claim
61 words
A resistance controllable indicator in accordance with claim 1, characterized by said feed back means comprising a capacitor in circuit between said indicator circuit and the base electrode of said second transistor, and further characterized by said second transistor circuit including said spaced contacts, being connected from one side of said power source to the base electrode of said second transistor.
Claim 4
Dependent Claim
35 words
A resistance controllable indicator in accordance with claim 2, characterized by a case enlosing said frequency generating circuit, with said spaced contacts Mounted on the wall structure of said case to provide externally accessible terminals.
Claim 5
Dependent Claim
34 words
A resistance controllable indicator in accordance with claim 3, characterized by said externally accessible terminals being in the form of contact strips affixed to a wall of said case and exposed to manual contact.
Claim 6
Dependent Claim
19 words
A resistance controllable indicator in accordance with claim 2, characterized by said frequency indication means as including a speaker.
Claim 7
Dependent Claim
36 words
A resistance controllable device in accordance with claim 2, characterized by said practically infinite resistance comprising a base plate of insulation and a pair of wires arranged in spaced relationship to each other on said plate.
References Cited (Backward Citations)
US2582629A
Cited
US2988708A
Cited
US2918054A
Cited
US3302102A
Cited
US3245068A
Cited
US3359425A
Cited
US3412326A
Cited
US3689832A
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 |