Composite Pcb; 1 ) Power Source Section - Kyocera Mita DC-2560 Service Manual

2-3-1 Composite PCB

(1) Power source section
Noise filter
circuit 2
MSW
AC
input
Noise filter
circuit 1
Figure 2-3-1 Power source section block diagram
Power source section of the composite PCB (CPCB) consists of the circuit shown in
Figure 2-3-1 to generate from the AC input into stable 24 V and 5 V DC output.
In the power source circuit, the AC input is converted into DC voltage, after it is
stabilized in the active filter circuit, and the DC voltage is converted to the pulse
waveform switching with FET (Q102).
The pulse waveform is applied to the primary side of transformer (TRNS), the pulse
waveform induced on the secondary side is rectified and smoothed into a 24 V DC
output.
5 V DC output is obtained by step-down 24 V DC output with the switching regulator.
TRNS
Rectifier
/active
filter
FET
circuit
Q102
Switching control/
overcurrent
detection circuit
PC2
PC1
24 V DC
output/
error
detection
circuit
Overvoltage
detection
circuit
5 V DC
output
circuit
1AH
24 V DC
output
5 V DC
output
2-3-1