Installation manual

38
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Both the collector and emitter of the phototransistor are on J4, providing the
capability to drive either sinking or sourcing loads.
Sinking Load
Current Limiting Resistor
50 mA MAX
External
Power Supply
30 VDC MAX
DC
+
-
An opto isolator is being driven in this example. The current through the output
needs to be limited to 50 mA or less, which is accomplished by selecting an
appropriate current limiting resistor. The voltage of the external power source
needs to be 30 VDC or less and can be the same source used to provide
power to the inputs.
Sourcing Load
Current Limiting Resistor
50 mA MAX
External
Power Supply
30 VDC MAX
Relay
Coil
Clamp
Diode
DC
+
-
In this example, a relay coil is being driven. The current through the coil needs
to be limited to 50 mA or less, which is accomplished by selecting an
appropriate value of current limiting resistor.
The voltage of the external power source needs to be 30 VDC or less and can
be the same source used to provide power to the inputs. A clamp diode must
be added across the coil to clamp the voltage during turn-off.