[sci.electronics] Telephone Ring Detector IC?

cook@gaia.UUCP (Forrest Cook) (10/28/87)

Does anybody out there have any experience with Telephone ring detector
chips?  The circuit that I have used is:

O----/\/\/-----(| |)---   <-light->  ---(/\/\/)------O 5 Volts
     150K	NE-2  |              |   CdS Cell
Phone Line	      |              |---------------O To Schmitt Trigger
		      |              |   2K
O----------------------              ----/\/\/-------O Ground

This works but is large and ugly.  Who makes the ring detector chips
and are they very reliable?

Thanks in advance,
Forrest Cook