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Install the optoisolator
The opto isolator comes in a 6-pin DIP (Dual Inline Package). Pin 1 on the PCB is
indicated by the square pad. Pin 1 on the opto-isolator package can be identified by the
dot on the package, refer to Figure 3. Make sure to install the opto with the correct
orientation.
Figure 3-Pin 1 of the opto-isolator is indicated by the dot and the ridge in the package
Opto isolator installation – watch the orientation!
Designation Type, Package
Rating, Marking, Description
Done? (
)
U1
4N35, 6 pin DIP
4N35 opto-isolator
Figure 4-Although more subtle, notice that the Q4 has a square side and a round side
