ringdown

listen to the pronunciation of ringdown
İngilizce - İngilizce
A signal to a telephone operator that both rings a bell and allows a relay to drop
  In telephony, a method of signaling an operator in which telephone ringing current is sent over the line to operate a lamp and cause the drop of a self-locking relay (188)  Note 1: Ringdown (a) is used in manual operation, as distinguished from dialing, (b) uses a continuous or pulsed ac signal transmitted over the line, and (c) may be used with or without a switchboard (188)  Note 2: The term "ringdown" originated in magneto telephone signaling in which cranking the magneto in a telephone set would not only "ring" its bell but also cause a lever to fall "down" at the central office switchboard
Method of signaling where one incoming signal is activated by alternating (ringing) current over the circuit
A circuit or a method of signaling where the incoming signal is actuated by alternating current over the circuit
A signaling method in which the incoming signal is actuated by alternating current (AC) over the circuit