LG D237IPS, Service Manual, Page: 19 / 29

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Copyright © 2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
DESCRIPTION OF BLOCK DIAGRAM (LPB)
1) POWER INPUT : AC 100 ~ 240 V Input.
2) EMI NOISE FILTER CIRCUIT : Circuit to decrease noise to be flowed outside and to be generated in circuit. This is
consisted of high frequency filtering capacitors and choke filter.
3) AC-DC RECTIFIED CIRCUIT : Circuit to change AC Voltage to high DC Voltage.
This is consisted of Bridge Diode, Capacitor.
4) NOISE REMOVAL CIRCUIT : This is consisted of RC circuit, deleting Peak Noise.
5) MAIN TRANSFORMER : This change primary High Voltage to designed secondary low Voltage.
6) 19V / 5V RECTIFIED AND FILTER CIRCUIT
: This regulate DC Voltage to input at Transformer for stable secondary voltage.
7) SWITCHING PWM CONTROL : This transfer primary DC Voltage to main transformer after switching effectively.
8) FEEDBACK : This is circuit to use circuit control, circuit protection function.
9) LED Driver SWITCHING FET
: This transfer DC Voltage to input from Power Side to LED Boost up Circuit after Switching effectively.
10) Boost up Circuit : This is circuit to make high DC Voltage more than LED String Voltage.
11) LED CONTROLLER : This is circuit to use LED circuit control, circuit protection function.