Quad state receiver
US3966149A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 1975 |
| Grant date | Jun 29, 1976 |
| Priority date | — |
| Expiry date | Mar 13, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB61L1/188
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A receiver is disclosed which is used in a transportation vehicle detection system to compare logic conditions in signals which are transmitted from a first vehicle pathway location, with logic conditions which are detected from signals received at a second vehicle pathway location. When first and second enable signals correspond, the signal from an oscillator is transmitted through two pairs of fail-safe AND gates and applied, through a fail-safe OR gate, to a latch circuit which signals the transportation system speed controller that no vehicle is present between the first and second pathway locations. When the first and second enable signals do not correspond, the signal from the oscillator is not transmitted through both pairs of fail-safe AND gates, there is no signal applied to the fail-safe OR gate, and no signal is applied to the latch circuit which signals the transportation system speed controller that a vehicle is present between the first and second pathway locations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.