EP 0363362 A4 19910320 - TELEPHONE SUBSET CIRCUIT ARRANGEMENT
Title (en)
TELEPHONE SUBSET CIRCUIT ARRANGEMENT
Publication
Application
Priority
AU PI133987 A 19870409
Abstract (en)
[origin: WO8808234A1] A telephone subset circuit arrangement which includes a capacitor (C1) that provides a current source for the circuits' dialler chip (1). Initially, with the capacitor discharged, upon connexion of the line terminals (L1 and L2) to an exchange line, current flows via the line terminal (L1) and a bleed resistor (R1) to cause a first transistor (TR1) to switch on thereby rendering the circuits' line switch (2) conducting. The capacitor is charged via the operated line switch by line current and when the voltage level across the capacitor reaches the minimum operating voltage of the dialler chip, a circuit comprising a second transistor (TR2) switches the first transistor off which in turn switches off the line switch. The dialler chip now has sufficient power available to it to operate the line switch whenever the hook-switch (HS) is operated.
IPC 1-7
IPC 8 full level
H04M 1/274 (2006.01); H04M 1/31 (2006.01); H04M 19/08 (2006.01)
CPC (source: EP)
H04M 1/312 (2013.01); H04M 19/08 (2013.01)
Citation (search report)
- No further relevant documents have been disclosed.
- See references of WO 8808234A1
Designated contracting state (EPC)
BE DE FR IT
DOCDB simple family (publication)
WO 8808234 A1 19881020; AU 1344988 A 19881104; AU 606397 B2 19910207; DK 683888 A 19890207; DK 683888 D0 19881208; EP 0363362 A1 19900418; EP 0363362 A4 19910320; JP H02503254 A 19901004
DOCDB simple family (application)
AU 8800046 W 19880222; AU 1344988 A 19880222; DK 683888 A 19881208; EP 88901774 A 19880222; JP 50178788 A 19880222