Inventors:
Jeffrey P. Davis - Ham Lake MN
Duane Francis Wald - Plymouth MN
Timothy D. Gunn - Mounds View MN
Assignee:
Multi-Tech Systems, Inc. - Mounds View MN
International Classification:
H04M 322
Abstract:
A communications interface having an isolation circuit for signals from a plain old telephone set (POTS) device to communications electronics. The communications interface having an isolated power supply. The isolated power supply including a flyback transformer for a current loop supply and an isolated power source The telephone line isolation circuit having an optically isolated off-hook detection circuit and an isolation transformer for isolating communication electronics from the telephone current loop. The telephone line isolation circuit providing a ringing circuit for ringing a current loop device, such as a standard plain old telephone system (POTS) device.
