Converter Circuit - NEC MultiSync FP1350 Service Manual

8-3. Converter Circuit

The converter circuit consists of the primary winding of T601, a switching device TR1(internal IC621) and
surge absorbers (C611, R605 and D603) which are connected to the primary winding of T601.
The oscillating signal through IC621 pin 5,Q624,R622 and C621 applied to IC621 pin 3(the base of TR1) so
that the collector-emitter is turned ON and OFF. In result, the oscillating voltage is applied to the primary
winding of T601.
D601
D601
IC621
DRIVE
DRIVE CIRCUIT
SINK
TR1
C
B
E
(Fig.8-3) Converter Circuit
C623
C611
Q624
5
R641
Q625
R622
4
+
R623
C621
-
3
B
1
C
2
GND
R625
8-42
T601
R605
D603
L601