Method and apparatus for determining proper installation of alarm devices
US6459370B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 5, 1999 |
| Grant date | Oct 1, 2002 |
| Priority date | — |
| Expiry date | May 5, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B29/06
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Jumper and ground faults are detected within an alarm system. Jumper detection applies to devices having two or more functions (e.g., audible horn and visual strobe). When operated with a single circuit, jumpers typically remain installed in such devices to provide power to all functions. However, if the devices are installed in alarm systems equipped with multiple functions, the jumpers should be removed to allow functions to operate independently and correctly. To detect unremoved jumpers, all loops to separate functions except one are isolated. After isolation, a predetermined signal is presented to the non-isolated loop and current is compared to a reference value. If jumpers exist between this non-isolated loop and another supposedly isolated loop, the additional parallel resistance produces an abnormal signal. To perform ground fault detection, lines of devices may be sequentially isolated (i.e., disconnected) at the control panel via software control until a previously detected ground fault disappears. The line that is isolated and which causes the fault to disappear is the line containing the fault.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.