Voltage enhancement circuit for central station monitored alarm systems
US4083039A · kind A · utility
Assignees
Inventor
Key dates
| Filing date | Oct 23, 1975 |
| Grant date | Apr 4, 1978 |
| Priority date | — |
| Expiry date | Oct 23, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M11/04
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A voltage enhancement device in the nature of a DC-to-DC converter is used in a centrally monitored alarm system of the type having at least one alarm detection device at a first location, an alarm monitoring panel at a second location, and telephone lines interconnecting the device in the panel. The telephone lines have an internal resistance which causes some of the voltage applied at the input of the lines at the first location to be dropped thereacross with resultant decrease in voltage at the second location. The alarm monitoring panel includes an indicator, such as a meter, which requires a minimum detectable voltage to provide a suitable indication or deflection of the meter to distinguish between an alarm, normal or trouble condition at the first location. The DC-to-DC converter only utilizes the voltage available at the first location and increases the magnitude of the voltage to compensate for the internal line resistance to assure that the voltage which is available at the second location is at least equal to the minimum detectable voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.