1-8. BLOCK DIAGRAM PRESENTATION. (CONT)
RING ACKNOWLEDGE TONE DETECTOR CIRCUIT (CONT)
570 Hz Limiter Circuit
This circuit produces a square wave output form the 570 HZ amplifier output signal.
The output signal of this circuit controls the bandwidth of the detector output circuit. It is designed to conduct at the 2 dB point on the
positive part of the signal.
DETECTOR OUTPUT CIRCUIT
The detector output circuit is made up of five switching stages designed to perform the following functions:
Energize the 570 HZ integrator when acknowledge signals are received.
Energize the tone ringer when 570 HZ signal is present and stop he tone ringer during sending of dual tone multifrequency (DTMF)