Chapter 6. Power Supply Unit - Sharp UP-5700 Service Manual

CHAPTER 6. POWER SUPPLY UNIT

1. General
This power unit is used for UP-5700. The AC input voltage is AC90
UL1950.CSA950.SS-J. The outputs are +5V, +12V, and –12V.
The other functions include ACL signal, PHSNS signal, PHOLD signal, overvoltage protection against power abnormality, and overcurrent protection
which protects the power from an overload.
2. Block diagram
N/F
RLY1
section
PHSNS
Detector section
Convertor section
Rectifying
section
Control
section
Output monitor
Overvoltage protection
PHOLD circuit
138V. The safety standard conforms to Electrical regulations
Rectifying
section
Rectifying
Regulator
section
Rectifying
Regulator
section
Rectifying Power of
section detection
6 – 1
PHSNS
+5V
Temperature
protection
GND
+12V
GND
GND
-12V
ACL
PHOLD