Selective paging and intercommunication system

Details Selective paging and intercommunication system Selective paging and intercommunication system

1980-05-21

1983-03-22

Popek, Joseph A.

179 37, H04M 1300

Patent

active

043777260

ABSTRACT:
A battery powered paging and intercommunication system for application in a mine or other environment where it is necessary to conserve battery power comprises a plurality of transceivers electrically coupled to a common pair of signal lines. Each of the transceivers includes a push-to-talk switch for applying voice signals onto the lines as well as a push-to-page switch that amplifies received voice signals for reproduction through a loudspeaker. Each transceiver also includes dual tone multifrequency (DTMF) encoder and decoder circuitry for addressing a preselected transceiver on the lines for paging. A timer circuit within the transceiver limits the period of time the transceiver limits the period of time the transceiver is in the paging mode to reduce battery consumption. As a system check during paging, the called transceiver generates "beep-back" signals on the lines indicating to the calling transceiver that it is receiving paging signals. A second timer circuit controls a light flasher at the called transceiver to serve as a call back signal.

REFERENCES:
patent: 3909547 (1975-09-01), Day
patent: 3941933 (1976-03-01), Shields
patent: 3941944 (1976-03-01), McIntosh
patent: 4258230 (1981-03-01), Heller et al.
NASA Tech. Briefs, "A Telephone Multiline Signaling System", vol. 4, No. 1, p. 33, Spring, 1979.

Affiliated with

Also associated with

Rating

Selective paging and intercommunication system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Selective paging and intercommunication system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Selective paging and intercommunication system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1870461