Chapter 2—Functional Descriptions
2–8
Model 330, 340SC, and 370SC Service Manual
2.
+24V Standby and Arc Lamp power supplies turn on.
3.
When Arc Lamp lights (run voltage sensed by a window comparator in the
SPS), SPS pulls /LAMPLIT line low.
4.
SCB senses /LAMPLIT low and awaits further instructions.
Electronics only power-up:
1.
Upon receipt of Electronics-On command, SCB pulls /FANENBL and
/LVPSNBL lines low.
2.
+24V Standby and Low voltage supplies turn on.
3.
SCB 5V supply at correct level and enters normal program
sequence, lamp can be turned on at any time.
Table 2-1
System Power Supply Voltage Distribution
Voltage
F
a
n
HV
PS
CRT
SCB
HDB
VDB
VPB
RTG
VAB
Arc
Lamp/
Ignitor
+5v
+5v Stb
+6.3v
+15v
-15v
+24v
+24v Stb
+48v
+107v
+170v