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April 7, 2019, ©
Elcon
, Switzerland
EL-31_V2.1b_en.docx
Component 11
Component 12
Component 13
Component 14
Component 15
Component 16
Component 17
Component 18
Component 19
Component 20
Table 3
2.2 Step by Step assembly and testing of printed circuit boards
2.2.1 Assembling the pcb
For the placement drawings of the top and bottom of the pcb refer to Chapter 5.3 (Figure 20
and Figure 21). The SMD components are already assembled.
Populate the following components, using the parts list (Table 2).
R1 to R13, resistors
X1, Crystal 8MHz
→
The crystal is soldered with a small distance to the circuit board:
Cut a paper or a plastic strip 4mm x 30mm (thickness approx. 0.2mm) and place it on
the component side between the two quartz ports. After soldering, remove the strip.
C1 to 12, capacitors
→
mind the polarity in electrolytic capacitors!
U1 to U6, 7-segment LED display 10 pin
→
note installation direction!
U7, IC MAX7221 or AS1106 LED Display-Driver 24 pin
→
note installation direction!
The LEDs must be very accurately aligned in a straight line! Solder only 2 pins (diago-
nal) first, so that the alignment can still be corrected.
U8, IC PIC18F2550 microcontroller
→
note the installation direction!
U9, IC SN7400N Quad 2-Port NAND
→
note the installation direction!
U10, IC TSOP4838 IR Receiver
→
leads have to be turned by 90°.
B1, AT-1220-TT-5-R Buzzer
P1 and P3, pin connectors 2x7
The pin connectors are fitted on the backside and soldered on the front side. The pin
strips must lie flat and stay perpendicular to the pcb.
J2, Solder the 30 cm long white wire
→
This wire will be connected to the 13.8V supply
voltage of the transceiver after installation of the display board into the FT-301D.