Sony RM-PJM50, Manual

Page: 68 / 178

4-8
VPL-FX50
EMI
Filter
Relay Control
Circuit
QC Board
Power Source
Active Filter
Circuit Power
Source
Lamp Power Source
DC
Voltage
Approx.
0.78A
VCC
Lamp
AC Voltage
R100
22 Z , 5W
RY1000
D1002
Template Fuse
Fig.5 Lamp Run-away Countermeasure Circuit
(2) Operations after POWER ON
Receiving POWER ON signal from the microproces-
sor, the CN1207 pin
1
becomes “High” and the
signal are input to the comparator IC1205 pin
5
.
The comparator IC1205 and its peripheral parts
configure a delay circuit.
After about 0.3 second this delay circuit makes the pin
1
of IC1205 “Low”, turns Power ON
.
OFF switches
Q1205, Q1210, Q1214 and Q1206 ON in the power
supply line and supplies working voltages to the later
circuits.
(3) Details of Parts
.
R1220
Circuit Power Supply protection resistor
In case a trouble is occurred in the later stage, this
resistor makes the lines off and so protects other
parts.
.
IC1200
IC 1200 is to control the circuit power supply,
controlling current resonance circuit.
.
T1200
Switching Regulator Transformer for current
resonance
.
C1210
Film condenser for current resonance to structure
the circuit with the T1200 coils (L components).
4-4-1-4. DC-DC Converter
(1) DC-DC Converter and Switching Regulator for FAN
1, 2, 3, 4
After POWER ON, the DC-DC Converter IC1203
received the secondary output of 17 Volt (16.8
±
0.8
V) from the T1200, steps-down it to 12 V (11.5
±
0.8
V) applicable to other signal circuits.
In addition, the DC-DC Converter IC1203 also
provides this 12 V with the Switching regulators
(IC1209, IC1208, C1207 and IC1206) that correspond
respective to FAN1 (Bottom), FAN2 (Lamp sides),
FAN3 (Front), and FAN4 (For the lamp).
The microprocessor in the C board reads out the value
of resistance of Thyristor, TH5000 (Value changes
subject to the temperature) and then outputs the
voltage to the GA board CN1207 pin
5
and
6
through the buffer in the same board.
Such the input voltage to the pin
5
provides electric
current with the regulator IC1209 for the FAN1 and
with the DC-DC converter IC2103 ADJ terminal while
the voltage input to the pin
6
does with IC1208/
FAN2, IC1207/FAN3 and IC1206/FAN4 each ADJ
terminal.
To the output VC through the buffer mentioned on the
above, each IC output is controlled as the follows.