US4247790A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Failsafe train vehicle control signal threshold detector apparatus
Assignee: Bombardier Transportation Holdings USA Inc
•
Filing: 1976-01-22
•
Granted: 1981-01-27
•
Expires: 1996-01-22
Abstract
Abstract A more failsafe signal voltage threshold determining apparatus is disclosed for operation in a train vehicle control system, and which utilizes the forward voltage drop characteristic of an input light emitting diode of an optical isolator device as a train vehicle control signal threshold reference. The detector transistor of the optical isolator device provides an output control signal in response to an input train vehicle control signal applied to the light emitting diode which has a voltage level high enough to overcome the light emitting diode voltage drop.
Inventors
- 👤 Arun P. Sahasrabudhe
- 👤 Thomas C. Matty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:25
CPC Classifications
B; B61; B61L; B61L1/00; B61L1/20; H; H03; H03K; H03K17/00; H03K17/51; H03K17/78; H03K17/795; H03K17/7955
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
111 words
In train vehicle control signal threshold detector apparatus operative with a source of an offset voltage, the combination of: means for providing a train vehicle alternating current input control signal; means responsive to said alternating current input control signal for providing a photon energy output when the voltage of said input signal is above a predetermined threshold voltage reference, and means responsive to said photon energy output for providing an output signal proportional to said photon energy output, with each of said photon energy output providing means and said output signal providing means being coupled to said offset voltage source for preventing direct current reduction of said predetermined threshold voltage reference.
Claim 2
Dependent Claim
111 words
In train vehicle control signal threshold detector apparatus operative with a source of an offset voltage, the combination of: means for providing a train vehicle alternating current input control signal; means responsive to said alternating current input control signal for providing a photon energy output when the voltage of said input signal is above a predetermined threshold voltage reference, and means responsive to said photon energy output for providing an output signal proportional to said photon energy output, with each of said photon energy output providing means and said output signal providing means being coupled to said offset voltage source for preventing direct current reduction of said predetermined threshold voltage reference.
Claim 3
Dependent Claim
45 words
The train vehicle control signal threshold detector apparatus of claim 1, with said photon energy output being proportional to the amplitude of the input signal current flow through said photon energy output providing means and with said offset voltage source providing a negative offset voltage.
Claim 4
Dependent Claim
39 words
The train vehicle control signal threshold detector apparatus of claim 1, with said photon energy output providing means having a predetermined work function which must be exceeded by the input signal voltage before said photon energy output is provided.
Claim 5
Dependent Claim
31 words
The train vehicle control signal threshold detector apparatus of claim 1, with said photon energy output providing means having a forward voltage drop characteristic operative as said predetermined threshold voltage reference.
References Cited (Backward Citations)
US3816745A
Cited
US3826930A
Cited
US3925709A
Cited
US3995173A
Cited
US3964041A
Cited
US3999133A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-27 | 1984-07-28 | 1985-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-27 | 1988-07-28 | 1989-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-27 | 1992-07-28 | 1993-01-27 | $7700.00 | Window Closed / Lapsed |