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POWER Circuit Operation
Power Unit (Including m-COM operation in regard to POWER)
• When the commercial power supply is given from the AC inlet, the POWER unit begins to generate outputs
of M+7V and M+14V for the µ-COM system. M+7V is fed from Pin 3 of the PM to IC9504 in order to turn on
SW (S2601) of the main power supply. As a result, M+5V is fed to the µ-COM (IC9501). This causes the
POWER and POSAVE signals to be fed to the POWER unit, which therefore begins to be operated.
• When the POWER signal at "H" level is fed from Pin 4 of the PM, the RL1 is turned on to generate the
various power outputs (D+5V, A+14V, A+7V, S+13V, S-13V) for the signal system. These power outputs are
then supplied to various circuits of signal system.
• When the POSAVE signal at "H" level is fed from Pin 5 of the PM, the various power outputs (D+170V,
D+70V) begin to be generated for the HV system. Thus power is fed to the plasma display module.
• When the internal temperature of the POWER unit attains about 100°C, the T-ALM signal begins to send the
"L" signal from Pin 0 of the PN to the MAIN PWB (µ-COM). The µ-COM causes the POWER and POSAVE
signals to be turned at the "L" potential in order to turn off the power supply. Thus the LED begins to flash in
red.
• When the module supplies an input of the LVP signal at "L" to Pin 73 of the AD (MAIN) and Pin 21 of the PD
(POWER unit), the m-COM causes the POWER and POSAVE signals to be turned at the "L" potential and
simultaneously makes the LED flash in red and green reciprocally. The POWER unit turns off all the power
supplies other than M+7V and M+14V.
• The POMUTE signal firstly detects the condition of AC OFF and generates an output of "L" to Pin 6 of the
PM. This signal is fed to Pin 9 of the m-COM and Pin 4 of the AE (AUDIO unit). This action is taken to
identify the condition of commercial power off due to a service interruption or any other possible causes (for
the prevention of mis-operation). It is also intended for audio MUTE.
CIRCUIT DESCRIPTION
6-12
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