1-9. OPERATIONAL MODES AND CONTROLS. (CONT)
OUTGOING CALL WITH MODE SELECTOR SWITCH IN AC SUPV POSITION (CONT)
Once the 2250 Hz seize oscillator is energized, the signal is coupled to the send amplifier, amplified, and sent to the switching facility.
The switching facility acknowledges the request for service and the following functions occur in the order given.
A seize acknowledge signal (570 Hz) is sent to the receive terminals of the telephone set and is inductively coupled to the input of the
570 Hz amplifier in the ring acknowledge tone detector circuit.
The acknowledge signal is amplified and the output of the detector energizes the integrator circuit. The integrator circuit provides a dc
output which energizes the latch circuit.
The latch circuit, when energized, stops the seize oscillator and energizes the receive amplifier and sidetone gate circuit.