Conrad FS20 IRP Bedienungsanleitung Seite 43

Flush-mounted transmitter "FS20 S4U"
If you want to convert a flush-mounted transmitter that is already in
operation, first separate it completely from the power supply and the
connected installation switches.
Then you may carefully dismantle the housing. To do so, carefully push in the two latches on
the connection side to remove the housing cover.
Then carefully remove the electronics from the housing. Now install the photo diode as
indicated in the illustration on the bottom of the control board (seen from the side with the four
connection pins). The anode is soldered onto the ground contact minus) of the electric contact
C5 located on the top. Solder on the cathode to R7 directly in front to the right of the controller
pads.
Shape the connections for the photo diode in such a way that they cannot cause
a short circuit on the board.
Now drill a boring on the side (diameter ca. 2-3 mm) below TA4 (approx. at half of the housing
height) to be able to program the device after installation of the housing through this opening
without touching it. Then cover the opening with a piece of adhesive tape to prevent
penetration of dust, cable ends, etc.
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