| 摘要 |
<p>Known telecommunication devices like telephones not having a separate supply get their supply via a telecommunication line after a mouthpiece has been lifted and by rectifying a ringing signal before said mouthpiece has been lifted, and are therefore not able to distinguish between a mouthpiece being lifted for making an outgoing call and being lifted during a silence of a ringing signal indicating an incoming call. This distinguishment, which is necessary for some display functions, can be made by introducing a supplyless memory for storing a memory signal in response to said ringing signal, which supplyless memory preferably comprises a capacitor which is charged during a ring of said ringing signal and which is discharged only a little during a silence of said ringing signal. <IMAGE></p> |
