Telephone answering unit housed in telephone - has two control switches working through gate circuits into answering unit circuitry and local circuit to switch-hook springs

摘要

Switching procedure and circuitry to connect a telephone answering unit into circuit which is housed in a normal size domestic telephone instrument. The answering circuitry (AB) is controlled by the conditions output from two preceding gate circuits (GS1,GS2). One gate output (GS1) is used to switch the answering unit (AB) into the prepared mode and the second (GS2) operates through a short pulse circuit (IAS) to send a start pulse into the circuit which starts the playback. Three switch units (T,S,Gu) and a logic circuit (LS) are used at the inputs to the controlling gates (GS1,GS2) to determine the user requirements. One switch (S) is used to switch the answering unit into or out of circuit. The second switch (T) control replay and is coupled via the logic circuit (LS) to the switch-hook springs (gu) so that one is operated by the second switch (T). During the entire recording or standby recording mode, a signal must remain on the output of the first gate (GS1). For replay a short pulse start is required through the second gate (GS2).