NEC MultiSync 3D JC-1404HME Service Manual page 50

(e) Error detection amplifier circuits
The output voltage 85V is divided by the network resistors. This divided voltage is compared to
the reference voltage at the error amplifier IC651. An error signal is applied to the control
circuit via the photocoupler PC601.
R662
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(Fig. 2-1-5) Error Detection Amplifier Circuit
(f) Oscillating circuit, control circuit, and drive circuit
The oscillating, control, and drive circuits are comprised in IC601.
IC601 has a built-in oscillator whose frequency is determined by R622, C617, and R619
connected to pins 9, 10, and 11, respectively.
The output of the error detection amplifier circuit is fed back to the control circuit from pin 8
via PC601 to control the duty cycle of 0603 so that output voltage is kept constant.
IC601
(Fig. 2-1-6) Oscillating & Control Circuits
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