3 / 4 page

OLP Series
Polysulphone optical liquid level switches
3/4
September 2008 / 635
www.sensortechnics.com
ELECTRICAL CONNECTION (cont.)
TTL compatible (high in air)
Push-Pull (current sinking and sourcing)
Basic
Note: Customer has to select suitable resistors for chosen supply voltage. Pull-up resistor
R
P could be e.g. 10 kΩ depending on desired output. Forward voltage of LED is 1.3 V
and LED current should be 10 mA (depending on application liquid).
R
LED can be calculated as follows (e.g. for VS=12 V):
Ω
≈
Ω
=
−
=
−
=
k
1
.
1
1070
01
.
0
3
.
1
12
mA
10
V
)
3
.
1
V
(
R
S
LED
Blue
Green
Red
+V
Output
GND
S
4.7
TTL compatible (low in air)
Blue
Green
Red
+V
Output
GND
S
R
L
Blue
Green
Red
+V
Output
GND
S
R
L
GND
Red
Blue
Green
LED
R
+V
S
Output
P
R