Page 15 - Wagp_InterfaceElectronic_Volume4_2015_US.pdf

WAGO Optocouplers 0

13
WAGO optocouplers: the modern Input circuit
and efficient alternative
According to the type, triggering the A1 1
+
+
As the connecting element between optocoupler modules is performed via
process interface and electronic control direct voltage (residual ripple RR <6%) or R L
and signalling systems, the optocoupler AC voltage (50–60 Hz).
2
A2
modules offer the following advantages In the DC type, a reverse voltage – –
compared with mechanical relays: protection diode is always provided; 2-wire output
• long service life, because there is no in the AC type optocoupler element,
mechanical wear a rectifier is included.
The optocoupler modules are equipped
• high switching frequency because of with a LED function indication at either A1 1
fast switching times the input side or at the load side, as + +
• unaffected by vibrationn shown in the wiring diagram. A2 3
–

R L
• no contacts A2 2
– –
• “noiseless” switching
3-wire output positive switching
• low driving capacity.
For all interfaces between control and
load circuits that rely on these advan-
A1 1 A1 1
tages, WAGO AUTOMATION offers a + + + +
complete optocoupler range for the follo- R L R L
A2 3 A2 3
wing functions: – –
A2 2 A2 2
– – – –
• electrical isolation between input and DC triggering with LED function indication in the 3-wire output negative switching
output circuit triggering circuit
• adaptation to different signal levels
In addition to these different functional
• signal amplification. A1 1 outputs, the output voltage range an
The optocoupler modules are available + + R L the maximum switching current must be
in WAGO’s component plug technology A2 3 observed. Also note the correct polarity.
that is designed to plug directly into rail- – In order to protect the output transis tors,
mounted carrier terminal blocks. A2 2 inductive loads must always be equipped
–
–
The terminal blocks are fitted to the carri- with a protective circuit, e.g., a recove-
DC triggering with LED function indication in the
er rail and offer all advantages of CAGE load circuit ry diode. For other types of protective
®
CLAMP technology, which provides safe measures, the cut-off voltage peaks must
and maintenance-free connection of the be lower than the indicated cut-off volta-
signal wires for cross sections ranging A1 1 ge of the output transistors. For the AC
2
2
from 0.08 mm to 2.5 mm / ~ + R L outputs a Triac is used as the switching
AWG 28–12. A2 3 element.
~

In addition to optimizing space through
A2 2
the combination of terminal points and ~ –
the “function module,” maximum flexibili- AC triggering with LED function indication in the
ty and ease of service are also achieved. load circuit
Due to the low threshold voltages, care A1 ~
1
+
must be taken to ensure malfunctions are R L
not caused by the capacitance of long A2 Nullspannungsschalter 2
–
~
signal lines or the residual off-current of A2 2 ~
semiconductor devices. – ~

Output circuit
Depending on the application, an In order to avoid high turn-on currents,
optocoupler module for the AC or DC the AC output is equipped with a zero-
supply may be chosen. In the case of DC voltage switch which turns on the load at
outputs, they can be: the zero-voltage point. In the current zero-
crossing, the Triac will cut off the load,
• 2-wire output
in case inductive loads do not exceed
• 3-wire output positive switching the maximum switching voltage and the
• 3-wire output negative switching. maximum switching current.