DESCRIPTION OF BLOCK DIAGRAM
1. Line Filter & Associated Circuit.5. X-ray Protection.
This is used for suppressing noise of power input lineThis circuit detects the rectified DC voltage comes
flowing into the monitor and/or some noise generatedfrom the FBT pin 4. If the high voltage of the FBT
in this monitor flowing out through the power inputreaches up to about 30kV (abnormal state), H.V
line.control (IC802) detects. It stops B+voltage supplied to
That is to say, this circuit prevents interferencethe FBT (T701), and high voltage is not be generated,
between the monitor and other electric appliances.(In the normal state, the high voltage is about 26kV.)
2. Degauss Circuit & Coil.6. Micom(Microprocessor) Circuit.
The degauss circuit consists of the degaussing coil,The operating procedure of Micom (Microprocessor)
the PTC (Positive Temperature Coefficient) thermistorand its associated circuit is as follows:
(TH901), and the relay (RL901). This circuit eliminates
1) H and V sync signal is supplied from Signal Cable to the
abnormal color of the screen automatically by
Micom (IC401).
degaussing the slot mask in the CDT when turn on the
power switch.2) The Micom (IC401) distinguishes polarity and
When you need to degauss while using the monitor,frequency of Hand V sync.
select DEGAUSS on the OSD menu.
3) The Micom controls each OSD function signals.
(H-size, H-position, V-size, etc.)
3. SMPS (Switching Mode Power Supply).
4) The controlled data of each mode is stored in IC402.
This circuit works with power of 100~240V or
User can adjust screen condition by each OSD
200~240V (50/60Hz) specially for PFC version.
function. The data of the adjust screen condition is
The operation procedure is as follows:stored automatically.
1) AC input voltage is rectified and smoothed by
7. Horizontal and Vertical Synchronous Processor.
the bridge diode (D901) and the capacitor (C905).
This circuit generates the horizontal drive pulse and
2) The rectified voltage (DC voltage) is applied to the
the vertical drive pulse by taking sync-signal from
primary coil of the transformer (T901).
Signal Cable. This circuit consists of the
3) The control IC (IC901) generates switching pulseTDA4841(IC801) and the associated circuit.
to turn on and off the primary coil of the
transformer (T901) repeatedly.8. Oscillating Circuit for D/D Converter.
4) Depending on the turn ratio of the transformer, the This circuit generates the pulse wave which has the
secondary voltages appear at the secondary coil ofhorizontal period by taking the output of the
the transformer (T901).TDA4841(IC801).
5) These secondary voltages are rectified by each
9. D/D (DC to DC) Converter.
diode (D924, D926, D923, D922, D921, D920) and
operate the other circuits. (Deflection, VideoThis circuit supplies DC voltage to the horizontal
Amplifier, etc.)deflection output circuit by decreasing DC 192V which
is the secondary voltage of the SMPS in accordance
4. Display Power Management Circuit.with the input horizontal sync signal.
This circuit control power consumption of the monitor
10. D/D Drive & Convert Circuit.
by detecting H and V sync signal. There are stand-by
and suspend mode. When no horizontal or verticalThis circuit is used for supplying B+voltage to
sync signal input, the circuit consists of Q913, Q915horizontal deflection output transistor (Q801).
and IC401 control signal becomes stand-by and
suspend mode. ItOs power consumption is below 8W.11. Horizontal Deflection Output Circuit.
When no horizontal and vertical sync signal input, itOs
This circuit makes the horizontal deflection by
power consumption is below 1W.
supplying the saw-tooth current to the horizontal
deflection yoke.
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