Led Display Circuit - Toshiba e-STUDIO200L Service Manual

5.4.2

LED display circuit

1) Method of LED display
ex) Displaying "COPY".
LDON0
Transistor is turned ON when the LDON 0 signal becomes "L" level.
Also, when IC pin 17 changes to "L", the current flows from 5VL via the transistor to the LED
("COPY") to turn ON the LED ("COPY").
Conditions to turn ON the LED
(a) The transistor (Q3) connected to the LED anode is ON.
(b) The output from the cathode side of the LED is "L" level.
The LED turns ON when the conditions (a) and (b) are met.
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5VL
Current
"L"
Q3
( COPY )
Fig. 5-7
5 - 15
"L" 17
D7
G
R3
LED
IC
e-STUDIO200L/202L/203L/230/232/233/280/282/283
5
CONTROL PANEL