Ringing signal sending-out circuit

Telephonic communications – Centralized switching system – With generating of call associated substation signal

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

379418, H04M 302

Patent

active

047349360

ABSTRACT:
A circuit for sending out a ringing signal of a high voltage and a low frequency to a telephone set through a telephone line repeatedly with a predetermined time interval. In order to omit use of a high power oscillator and relays, a D.C. power supply of a high voltage is operatively connected to the telephone line through phototransistors of photocouplers being driven by a pulse signal having a low voltage and the low frequency under control of pulses occurring at the predetermined time intervals so that the ringing signal is sent out to the telephone set repeatedly with the predetermined time interval.

REFERENCES:
patent: 4220826 (1980-09-01), Kiss

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Ringing signal sending-out circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Ringing signal sending-out circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ringing signal sending-out circuit will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1093940

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.