Panasonic KX-FLB758RU Service Manual page 198

KX-FLB758RU
7.12.3. TRA(+) BIAS (Transfer(+) BIAS)/TRA(-) BIAS (Transfer(-) BIAS) UNIT
When the CHG REM terminal is "L" and the TRA CLK terminal is "Open", Transfer(-) BIAS(-1200V) is output from TRA OUTPUT
the moment Charge BIAS(-1200V) is output from CHG OUTPUT. When 8KHz PWM (pulse-width modulation) signal is input to the
TRA CLK terminal, Q101 turns ON by MC101, and TRA(+) CURRENT BIAS according to the PWM signal is output from TRA
OUTPUT. The PWM signal will be turned to a constant voltage by the resistor and the condenser, and input to the MC101. The
MC101 compares this voltage with the feedback voltage from T101 and controls the Q101. As for the transfer current, +30µA is
output when DUTY of the TRA CLK input signal is 0%, or +4µA is output when that is 70%.
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