US4661878A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Overvoltage protection circuit
Assignee: Motorola Solutions Inc
•
Filing: 1985-08-09
•
Granted: 1987-04-28
•
Expires: 2005-08-09
Abstract
Abstract An overvoltage protection circuit for directing a surge current on an input/output line, in particular, a telephone line, to a ground terminal when the surge current exceeds a predetermined level.
Inventors
- 👤 Leland T. Brown
- 👤 Byron G. Bynum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:47
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/18; H02; H02H; H02H9/00; H02H9/04; H02H9/041
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
147 words
An overvoltage protection circuit for directing a surge current on first and second telephone lines, each having respective input and output terminals, to a ground terminal when said surge current exceeds a predetermined level thereof comprising: a ground terminal; first and second telephone lines, each having respective input and output terminals; first and second diodes having respective anode and cathode terminals thereof, said first diode having said cathode terminal coupled to the input terminal of said first telephone line and said anode terminal connected to the output terminal of said first telephone line, said second diode having said anode terminal coupled to the input terminal of said second telephone line and said cathode terminal connected to the output terminal of said second telephone line; and first and second bilateral trigger devices respectively coupling the output terminals of said first and second telephone lines to said ground terminal.
Claim 2
Dependent Claim
147 words
An overvoltage protection circuit for directing a surge current on first and second telephone lines, each having respective input and output terminals, to a ground terminal when said surge current exceeds a predetermined level thereof comprising: a ground terminal; first and second telephone lines, each having respective input and output terminals; first and second diodes having respective anode and cathode terminals thereof, said first diode having said cathode terminal coupled to the input terminal of said first telephone line and said anode terminal connected to the output terminal of said first telephone line, said second diode having said anode terminal coupled to the input terminal of said second telephone line and said cathode terminal connected to the output terminal of said second telephone line; and first and second bilateral trigger devices respectively coupling the output terminals of said first and second telephone lines to said ground terminal.
Claim 3
Dependent Claim
17 words
The overvoltage protection circuit of claim 1 wherein said first and second bilateral trigger devices comprise SIDAC's.
Claim 4
Dependent Claim
126 words
An overvoltage protection circuit for directing a surge current on first and second telephone lines to a ground terminal when said surge current exceeds a predetermined level thereof comprising: a ground terminal; first and second telephone lines; a first diode having anode and cathode terminals, said anode terminal of said first diode coupled to said first telephone line; a second diode having anode and cathode terminals, said anode terminal of said second diode coupled to said second telephone line; and a TRIAC having first and second main terminals and a gate terminal, said first main terminal coupled to said cathode terminals of said first and second diodes, said second main terminal coupled to said ground terminal and said gate terminal for coupling to a reference voltage.
Claim 5
Dependent Claim
126 words
An overvoltage protection circuit for directing a surge current on first and second telephone lines to a ground terminal when said surge current exceeds a predetermined level thereof comprising: a ground terminal; first and second telephone lines; a first diode having anode and cathode terminals, said anode terminal of said first diode coupled to said first telephone line; a second diode having anode and cathode terminals, said anode terminal of said second diode coupled to said second telephone line; and a TRIAC having first and second main terminals and a gate terminal, said first main terminal coupled to said cathode terminals of said first and second diodes, said second main terminal coupled to said ground terminal and said gate terminal for coupling to a reference voltage.
References Cited (Backward Citations)
US3213349A
Cited
US3246206A
Cited
US3968407A
Cited
US4050018A
Cited
US4455586A
Cited
US4389695A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-04-27 | 1990-10-27 | 1991-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-27 | 1994-10-27 | 1995-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-27 | 1998-10-27 | 1999-04-28 | $7700.00 | Window Closed / Lapsed |