Service manual

THEORY
SERVICE MANUAL
Electrical
2-5
3.2. +24V Generator
The timing chart of the +24V generation circuit during idling is shown in Fig. 2.3.
Switching Q6 by #4 at 100 kHz boosts the input to a stable +24V.
Energy is accumulated in L1 while Q6 is ON and the power is transmitted to the output
side by the back electromotive force generated from the moment Q6 is turned OFF.
Stabilization to +24V is achieved by changing the ON-OFF duty ratio of Q6.
Fig. 2.3 Timing Chart of +24V Generation Circuit
3.3. +5V Generator
The timing chart of the +5V generation circuit during idling is shown in Fig. 2.4.
Switching Q12 by #4 at 100 kHz reduces the input voltage to a stable +5V.
While Q12 is ON, energy is supplied to L3, C31, and load. The energy accumulated in
L3 is supplied to load through D2. Stabilization to +5V is achieved by changing the ON-
OFF duty ratio of Q6.
Fig. 2.4 Timing Chart of +5V Generation Circuit