Toshiba TDP-TW100B, Service Manual

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6-18
The APS-M602 power supply circuit shown as (Fig.1)
1)Input Line Filter
A switching power supply generates a lot of electromagnetic noise. The function of the AC line Filter,
witch is made up of capacitors (e.g.C103) and inductor choke (e.g.101,L102),is to attenuate these
noise so that other equipments many not be affected.
The surge absorber Z101 which absorbs high voltage surge from the input lines. These are mounted on
the input filter.
*The fuse (F101) becomes open in order to protect other parts, when excessive current flows at
abnormal conditions.
*CN101 is connected thermo sensing element (e.g. Thermal protector.)
Power Supply is operated by CN104 shorted condition.
2) Power Factor Control Circuit
This circuit has 5 functions as below.
A) To generate stable voltage
B) To reduce input harmonic currents
C) Over current protection
D) Over voltage protection
E) (Inrush current suppression circuit)
A) Generate stable voltage
This circuit operate as step up to 370Vdc(type.)and voltage control.Actually,Q1,Q2(MC102)
are switched by MC101.
Initial voltage setting of 370V output(between pin 1 and pin 3 of CN102)has set at 370V(type.) by
VR101.(Input voltage :100Vac,max.load)
Operation of Power Supply (APS-M602)
Chapter 6
Fig.1
AC Inout
Input
Line Filter
CD/DC
Swintching
Converter
Secondary
Rectifier
Circuit
Feedback
Control
6.5V
3.4V
0V
(InrushCurrent
Suppression circuit)
Power factor
Control
Circuit
Output
Time Sharing
Multi-output
Control Circuit
0V
12V
15V
Lamp Output