Theory of Operation4–8 VITS100 NTSC VITS Inserter Instruction Manual
Current In
primary
Current In
secondaries
Voltage across
primary
Voltage across
+5V secondary
Voltage across
-5V secondary
Output
diodes on Output
diodes off
Q16 on Q16 off
VIN
+12V
–12V
–5V
+5V
+V
–V
–5.6V
+5.6V
0V
0V
+15V
–15V
C110
VIN
Housekeeping
winding
Q16,
Q17
T1
Figure 4–1: Inductor and switching transistor switching functions