Lamp; Operation Of Power Supply - Toshiba TDP-SW20 Service Manual

Operation of Power Supply

The APS-M526 power supply circuit can be divided into 2 main blocks (Fig.1)
1.the AC-DC converter, 2.the Time Sharing Multi-output control circuit.
These are shown as below.
AC
Input
1. The AC-DC Converter
The AC-DC converter can be further divided into sub-blocks as shown. (Fig. 2)
Input
AC
Line
Input
Filter
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 (eg. C101) and inductor choke (eg. L101), is to attenuate these noise so
that other equipments may not be affected.
Then, the power thermistor TH101 which restricts inrush current, and the surge absorber Z101 which
absorbes 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.
AC-DC
Converter

Lamp

Output
Fig. 1
Power
Factor
Correction
Control
Circuit
Lamp
Output
Fig. 2
Time
14V
Sharing
6-13V
Multi-output
COM
Control Circuit
Switching
Converter
Feedback
Control
15V
6.5V
0V
3.4V
0V
Rectifier &
6.5V
Output Filter
Output
2
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