Chapter 2—Functional Descriptions

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 senses +5V supply at correct level and enters normal program sequence, lamp can be turned on at any time.

Table 2-1System Power Supply Voltage Distribution

 

F

HV

 

 

 

 

 

 

 

Arc

Voltage

a

CRT

SCB

HDB

VDB

VPB

RTG

VAB

Lamp/

PS

 

n

 

 

 

 

 

 

 

Ignitor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+5v

 

 

 

 

 

 

 

 

 

 

+5v Stb

 

 

 

 

 

 

 

 

 

 

+6.3v

 

 

 

 

 

 

 

 

 

 

+15v

 

 

 

 

 

 

 

 

 

 

-15v

 

 

 

 

 

 

 

 

 

 

+24v

 

 

 

 

 

 

 

 

 

 

+24v Stb

 

 

 

 

 

 

 

 

 

 

+48v

 

 

 

 

 

 

 

 

 

 

+107v

 

 

 

 

 

 

 

 

 

 

+170v

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2–8

Model 330, 340SC, and 370SC Service Manual

Page 20
Image 20
JVC 340 SC, 330, 370 SC service manual Crt Scb Hdb Vdb Vpb Rtg Vab