HITACHI HDR080
Instrukcja Serwisowa

SERVICE MANUAL

16PW36-2 Power board
16MB07 E3 Board Power Consumption Voltage Current mA Power Watts 11.7W +12V +5V +3V3 Voltage ---Power Watts 19W +12V +5V +3V3

The TOPSwitch concept is used for power supply. TOP 234Y (IC1) is designed to work until 50 Watts in family of TOPSwitch_FX with 5 pins. The receiver works between 85 and 265 VAC mains voltage by using TOP 234Y in SMPS (Switch Mode Power Supply). In SMPS applications, secondary voltage regulation is adjusted according to the feedback voltage from the secondary side of transformer. The feedback voltages are 3.3V and 5V. This is connected to the comparator pin of TOP 234Y (IC1-pin1) via IC2 (Optocoupler). The comparator pin also protects the box against short circuits and overload. The supply voltage of TOP233Y(IC1) is between 2V and 3V at pin2. The TOP 234Y works at a fixed frequency. This frequency is fixed by RC oscillator at pin1. Pin3 and pin4 are ground and pin5 is the drain of the MOSFET, which is inside the TOP 234Y. Due to changes in Vcc, TOP234Y adjusts the duty cycle of the square wave in drain pin and regulates the secondary side of the transformer. Vcc voltage which changes between 2V and 3V is also used to regulate and protect. Output voltages of the transformer (TR2): (i) (ii) (iii) (iv) 3.3V: 5100 IC (IC101),flash memory (IC 1), tuner and other components. 5V: Front panel board, Tuner , and some ICs and circuits. 12V: hard disk and some other ic and circuits -25V :flaman voltage

POWER_ON STAND_BY

Current mA

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