Patent US3099827A successfully refreshed from Google Patents.
US3099827A
Expired / Lapsed
US
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Transistor indicator circuit
Assignee: McGraw Edison Co
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Filing: 1958-04-14
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Granted: 1963-07-30
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Expires: 1978-04-14
Abstract
No abstract record available.
Inventors
- 👤 Wu Bosco
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:33
CPC Classifications
G; G11; G11B; G11B25/00; G11B25/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
161 words
A DUAL FUNCTION INDICATOR FOR VOICE RECORDING EQUIPMENT OPERABLE FROM A DIRECT CURRENT SOURCE OF CURRENT AND ADAPTED TO PROVIDE BOTH A STEADY STATE ON-OFF INDICATION AND A VARIABLE SIGNAL-LEVEL INDICATION, COMPRISING AN ELECTRICALLY OPERABLE INDICATOR ELEMENT RESPONSIVE IN PROPORTION TO ENERGIZING CURRENT WITHIN A GIVEN CURRENT RANGE, AN ON-OFF SWITCH, A VOLTAGE CUT-DOWN RESISTOR, AN ELECTRICAL CIRCUIT SERIALLY INCLUDING SAID ON-OFF SWITCH, INDICATOR ELEMENT AND RESISTOR IN THE SEWUENCE HERE NAMED FOR SUPPYING CURRENT TO SAID INDICATOR ELEMENT WHEN SAID ON-OFF SWITCH IS CLOSED, A TRANSISTOR HAVING EMITTER, BASE AND COLLECTOR ELEMENT CONNECTED IN CLASS B ARRANGEMENT TO OPERATE AS A RECTIFIER, TWO OF SAID TRANSISTOR ELEMENTS BEING CONNECTED ACROSS SAID RESISTOR AND PROVIDING A FIXED IMPEDANCE THEREACROSS CAUSING SAID INDICATOR ELEMENT TO BE SUPPLIED WITH STEADY STATE CURRENT AT THE LOWER END OF SAID CURRENT RANGE WHEN NO SIGNAL IS APPLIED TO THE THIRD OF SAID TRANSISTOR ELEMENTS, AND MEANS FOR FEEDING ALTERNATING CURRENT VOICE-REPRESENTING SIGNALS FROM SAID RECORD
Claim 2
Dependent Claim
161 words
A DUAL FUNCTION INDICATOR FOR VOICE RECORDING EQUIPMENT OPERABLE FROM A DIRECT CURRENT SOURCE OF CURRENT AND ADAPTED TO PROVIDE BOTH A STEADY STATE ON-OFF INDICATION AND A VARIABLE SIGNAL-LEVEL INDICATION, COMPRISING AN ELECTRICALLY OPERABLE INDICATOR ELEMENT RESPONSIVE IN PROPORTION TO ENERGIZING CURRENT WITHIN A GIVEN CURRENT RANGE, AN ON-OFF SWITCH, A VOLTAGE CUT-DOWN RESISTOR, AN ELECTRICAL CIRCUIT SERIALLY INCLUDING SAID ON-OFF SWITCH, INDICATOR ELEMENT AND RESISTOR IN THE SEWUENCE HERE NAMED FOR SUPPYING CURRENT TO SAID INDICATOR ELEMENT WHEN SAID ON-OFF SWITCH IS CLOSED, A TRANSISTOR HAVING EMITTER, BASE AND COLLECTOR ELEMENT CONNECTED IN CLASS B ARRANGEMENT TO OPERATE AS A RECTIFIER, TWO OF SAID TRANSISTOR ELEMENTS BEING CONNECTED ACROSS SAID RESISTOR AND PROVIDING A FIXED IMPEDANCE THEREACROSS CAUSING SAID INDICATOR ELEMENT TO BE SUPPLIED WITH STEADY STATE CURRENT AT THE LOWER END OF SAID CURRENT RANGE WHEN NO SIGNAL IS APPLIED TO THE THIRD OF SAID TRANSISTOR ELEMENTS, AND MEANS FOR FEEDING ALTERNATING CURRENT VOICE-REPRESENTING SIGNALS FROM SAID RECORD
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) | 1966-07-29 | 1967-01-28 | 1967-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-07-29 | 1971-01-28 | 1971-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-07-29 | 1975-01-28 | 1975-07-30 | $7700.00 | Window Closed / Lapsed |