Mitsubishi WD-52627 Training Manual page 53

the same on all three of the PWB-POWER boards. It
is the original source for both Standby and Switched
supplies.
With the TV Off, AC from the PS connector is applied
to D9A00 through R9A01. The SMR generates +15V,
-15V and 18V standby supplies. The +15V and -15V
supplies are the source for switched +15V and -15V
supplies. The 18V supply is the source for all other
standby supplies.
Regulation is achieved by monitoring the 18V supply,
and comparing it to a reference in IC9A20, Any error
in voltage is coupled through PC9A10 to the SMR
IC9A10.
When the TV is switched ON the MAIN RELAY com-
mand goes High, closing K9A10 which removes cur-
rent limiting resistor R9A01 from the circuit.
V28 Chassis PWB-POWER Supplies
STANDBY SUPPLIES
STBY
AC Applied
Command
18VS 5VS
18VF 12VS
5VSL
+15VSA
-15VSA
V29 /V30 /V30+ /V31 Chassis PWB-POWER Supplies
STANDBY SUPPLIES
STBY
AC Applied
Command
18VS 5VS
18VF 12VS
5VSL
+15VSA
-15VSA
Although the SMR circuitry is the same on all PWB-
POWER boards, the Standby and Switched DC to DC
Converter circuitry does vary according to chassis type.
DC to DC Converters.
A comparison of DC supplies generated on the LCD
and DLP Power Supply boards is shown in Tables 5-2
and 5-3. Note that there is no Switched 12V or 5VR
supplies generated on the LCD Power board, and no
switched 18V supply is generated on the DLP Power
board.
The DC to DC Converter circuitry on the LCD Power
board is illustrated in Figure 5-3A. The DC to DC
Converter circuitry on the DLP Power board is shown
in Figure 5-3B. The difference in circuitry in Figure 5-
3 is high lighted by shading.
SWITCHED SUPPLIES
Sw Supply Command
18V 18V-ON
3.3V ENG-PWR-ON
+15VS PWR-ON
-15VS PWR-ON
340V LMP-RLY
Table 5-2
SWITCHED SUPPLIES
Sw Supply Command
3.3V ENG-PWR-ON
12V ENG-PWR-ON
5VR PWR-ON
+15VS PWR-ON
-15VS PWR-ON
340V LMP-RLY
Table 5-3
5-3