15.3. Ringer Circuit
If the ringer volume is set to low and an alarm tone is output from 39 pin, IC201 DSP and input to Q209. Then Q208 is turned off. If the ringer volume is set to high, Q208 turns on and results in a louder beep tone.
15.4. Sending Signal
The voice signal from the microphone input to pin 42 (CIDIP) and pin 41(CIDIN) of IC201 (DSP). CN203 is the headphone jack. When the headphone is connected, the Q206 detect it. The input from the microphone of the handset (CIDIN, CIDIP) is cut and the microphone signal from the headphone is input to pin 47 of IC201 (HMIN). Also the power for the microphone is supplied from Q211, and the power is turned OFF on standby.