xiX - Technical Manual Version 1.3
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3.10.2.4.4.
Output Wiring Example: LED Driving
LED can be driven directly by camera digital output. A series resistor must be used to limit LED current.
figure 3-57, LED Driving
LED series resistor can be calculated by the following equation:
psu
output
led
led
V
V
V
R
I
−
−
=
Where:
p s u
V
power supply voltage (5V to 24V)
output
V
voltage across digital output pins
(see.3.10.1 Optically isolated Digital Input )
led
V
LED forward voltage (see table below)
led
I
LED
current
Note:
•
Remember to use the appropriate resistor power rating
(
) =
× = (
−
) ×
Typical LED forward voltage
LED Colour
V
led
(typ.)
V
led
(max.)
Note
Standard
Red
1.7V
2.1V
Super
Bright
Red 1.85V
2.5V
Low
power
Red
1.7V
2.0V
Orange
2.0V 2.1V
Yellow
2.1V 2.2V
Green
1.9V 2.5V
Emerald
Green 2.1V
2.7V
Blue
2.5V 3.7V
White
2.8V 3.8V
Infra-Red
1.3V 1.8V
Opto coupler
table 3-41, digital output, LED driving
GND (Common IO Ground)
DIGITAL OUTPUT
Camera
Power Supply
R
LED
V
PSU
V
OUTPUT
