Canon FACSIMILE BASIC 2000 Service Manual page 297

In other words, when the output voltage is higher than the reference volt-
age, the duty ratio is lowered (the OFF time is increased), and when it is
lower than the reference voltage, the duty ratio is raised (the ON time is
increased) so that the output voltage is equal to the reference voltage at all
times.
ON
ON
OFF
Cycle Cycle
Low duty ratio
The following diagram shows a function block diagram of a switching reg-
ulator. Let's describes the functions of each block. The
called the "primary side" and the
a transformer provided as the boundary.
Primary side
AC
input
Protective Noise
circuits filter
Fig. 6-25 Function Block Diagram
ON
OFF OFF
Cycle
Fig. 6-24 Duty Ratio
DC output side the "secondary side" with
Surge
Rectifier Oscillation
prevention
circuit circuit
circuit
Control
circuit
FACSIMILE SYSTEM
ON ON
OFF
Cycle Cycle
High duty ratio
AC input side is
Secondary side
DC
output
Rectifier Smoothing
circuit circuit
Output error
amplification
circuit
6–25
1
2
3
4
5
6
ït
çi