Toshiba e-studio212 - LED Display Circuit

e-STUDIO182/212/242 © 2009 TOSHIBA TEC CORPORATION All rights reserved
CONTROL PANEL
5 - 6
5.4.2 LED display circuit
<Example> Lighting circuit method of “TEXT/PHOTO lamp”
Fig. 5-5
FET (Q1) is turned ON when the FET control signal (C0) becomes “L” level.
Then when the control signal (LEDM24) of the LED driver changes to “L” level, the current flows to the
cover open lamp (LED27) to turn ON the LED.
Conditions to turn ON the LED
The LED is turned ON only when the two conditions below are met.
1. The FET connected to the LED anode is ON.
2. The cathode side of the LED is “L” level.
Low
Low
TEXT/PHOTO lamp
(LED27)
R
+5V
LEDM24
Current
C0
Q1