Led Display Circuit - Toshiba e-studio3511, e-studio4511 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 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.
November 2003 © TOSHIBA TEC
5VL
Current
"L"
Q3
(COPY)
Fig. 5-405
5 - 11
"L" 17
D7
G
R3
LED
IC
e-STUDIO3511/4511 CONTROL PANEL
5