Abacus
+
Service Manual
rev 1.09
17
2.1.12. LCD Display Module with High Voltage Board
Display assembly contains the 240x128 dots graphics LCD display and the high voltage
board. LCD has a high voltage backlight lamp (high voltage board generates the required
voltage).
There is a special temperature compensation circuit in the display module, which makes
possible to use the LCD module in wide temperature ranges with the adjusted contrast.
High Voltage Board
(HVB) generates LCD backlight voltage (300V), aperture cleaning
voltage (150V), and measuring voltage (50V). The high voltage board is connected to the
system through the amplifier board and the COMB card. This unit contains INVC191
inverter, which is a high voltage, high frequency circuit producing suitable voltage for CCFL
(cold cathode fluorescent lamp) of the LCD.
The CFSW digital signal (from the COMB card) controls HVB: logical LOW turns inverter on.
The MVON digital signal (from the COMB card) switches the measuring voltage (50 V) on/off
by O1 opto switch.
Warning! Be careful with servicing this board in active state, because the high
voltage (300V) at LCD lamp connector can cause damages or electric shock.
Start key is a micro-switch, connected to the COMB card (through the Display ribbon cable).
The status LED indicates the actual status of the analyzer and it has two colors: red and blue
(See User‟s Manual). The LED has three pins and the actual color depends on the controlled
pins. Start key and status LED are controlled by COMB.
LCD &
Keypad
controller
LCD module
Keypad connector
Start key
connection and
status LED
LCD backlight
lamp
Connection
to LCD lamp
Connection to
COMB and
amplifier
Содержание Abacus +
Страница 6: ...Diatron MI PLC rev 1 09 6 ...
Страница 95: ...Abacus Service Manual rev 1 09 95 10 3 Abacus cabling diagram ...