Lamp monitor with latch circuit
US4550303A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 5, 1984 |
| Grant date | Oct 29, 1985 |
| Priority date | — |
| Expiry date | Apr 5, 2004 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60Q11/005
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A lamp monitor for detecting the failure of headlamps and other lamps on an automotive vehicle includes a failure detection circuit coupled to the lamp circuit to produce an output whenever the lamp circuit is operating and a failure occurs. A latch circuit responsive to the detector output and powered from the vehicle battery latches into a failure state when a lamp failure is detected and maintains that state even though the lamp circuit or the vehicle ignition circuit is switched off. The latch output triggers an indicator circuit to reveal an indication or warning when the vehicle ignition switch is turned on even though the lamp circuit is turned off and the ignition switch has been opened subsequent to the detected failure. Upon correction of the failure, the detector resets the latch circuit when the lamp circuit is actuated to disable the display.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.