2. Working principle
Realization of button function: when users are operating machine, button matrix circuit will produce
a button function code that transmits to main CPU inside decode chip, CPU performs the corresponding
switch to the function module inside system, and a control signal will produce to control OSD and panel
display part to make the corresponding display at the same time.
Panel display drive: when the serial data signals transmitted by decode chip is transmitting to panel
IC (PT6961), IC performs LED drive according to the information sent and displays the corresponding
content (controlled by software).
Indicator light control circuit: FSO pin of decode chip controls indicator light.
3. Definition and function of main jacks of panel
XS402 is connected to subsidiary panel, with the function of transmitting button control signal and
indicator light control voltage.
XS401 is connected to decode board and jack communicated with decode system. In which IR is
remote control output pin, +5V is panel power supply.
DATA is data transmission pin (dual direction) and controlled through STB, CLOCK is working clock
signal input displayed on panel.
FSO is the control pin to light by firmware, IR is remote control input pin.
XS403 is connected to button board to transmit button control signal.
3.2.17 Power circuit
1. Power circuit block diagram is shown as in the following figure 3.2.17.1:
Figure 3.2.17.1 Power circuit block diagram
Rectification
Absorption loop
Power grid
filtering
Power socket
Switch IC
Feedback
winding
Photoelectric
coupling
TLV
431
Sampling
circuit
Rectification
Filtering
+9V
LED+5V
+5V
+3.3V
-21V
Rectification
Rectification
Rectification
Rectification
Rectification
Filtering
Filtering
Filtering
Filtering
Filtering
FL-
FL+
Voltage
regulating circuit
-9V
VIPER22A
Filtering
HOST GND
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