P
PatentIndex
Search
Landscape
Sign in
Inventor
FRERICHS WERNER
DE
2 patents
Patents
2 patents
US4769835A
Sep 6, 1988
Method of and circuit arrangement for inserting dialling intervals between stored dialling digits
PHILIPS CORP
9 citations
68
US4723275A
Feb 2, 1988
Circuit arrangement for generating an acoustic ringing signal in a subscriber telephone set
PHILIPS CORP
6 citations
57