page 3 of 5
Assembly instruction
Assemble the kit in the order of these instructions. All components
(except the push buttons, rotary switch and 7-segment-elements)
are placed on the top side of the PCB (marked “top”) as close to
the PCB as possible and soldered on the bottom side of the PCB
(marked “Bottom”).
The Push buttons, rotary switch and 7-
segment-elements are placed on the bottom side and also
soldered on that side. All devices have to be placed abso-
lutely plane and equally and must not distance nor bias the
PCB.
Use a bending tool (e.g. Conrad 425869 – 62) for bending.
Cut the leads of components flush using a wire cutter after solder-
ing.
Solder cleanly and precisely!
1. Resistors
Bend the resistor leads for 7.5 mm pitch before insertion. To facili-
tate placing components on the PCB support the edges of the
board with the help of two books, for instance, to leave enough
space for the leads under the board. Insert the resistors on board
aligning the coloured rings of all the resistors in the same way to
make it easier to verify the value of the resistors later. Place a
suitable plane piece of wood or similar on top of the resistors on
board. Turn the board together with the wood upside down. The
underside of the board is now conveniently accessible for solder-
ing the components.
Solder one end of each resistor first and check that they are posi-
tioned properly before soldering the other end of each resistor.
R1, R2:
10kOhm
(brown, black, black, red, brown)
R3:
120Ohm
(brown, red, black, black, brown)
R4, R5:
100Ohm
(brown, black, black, black, brown)
R6-R11:
4,7kOhm
(yellow, lilac, black, brown, brown)
R12-R22:
22kOhm
(red, red, black, red, brown)
R23-R30:
680Ohm
(blue, grey, black, black, brown)
2. Socket for PIC, IC
Place and solder the PIC socket and IC3 with the notches accord-
ing to the component layout diagram on the PCB.
IC3:
LM339N
Sockel:
Socket for PIC
3. Ceramic capacitors
C1 - C3:
100nF
(104)
C6, C7:
220pF
(221)
4. Transistors and voltage regulator
The transistor and the voltage regulator can be placed simultane-
ously when proceeding similar to the resistors. Do not confuse the
transistors BC547 and BC557 with the voltage regulator 78L05!
Q1:
BC557
(flat bright labelled front)
Q2-Q4:
BC547
(flat bright labelled front)
IC2
78L05
(black front)
5. 7-segment-element, push buttons and rotary switch
Place and solder these in this order on the bottom side of the PCB.
Watch out to place 7-segment-elements with the correct orienta-
tion (dots downwards).
6. Electrolytic capacitors, watch polarity!
Electrolytic capacitors are placed reclined. The positive pole
(longer lead) of C4 and C5 must face to the left, so that minus
poles show towards the shielding.
C4, C5:
47µF
7. Wiring the SX-bus cable
Verify that one of the pins of the SX-bus cable is shortened. The
cable is soldered to the corresponding pads on the PCB. To do so
dismantle and tin the single wires for about 5 mm and route them
through the top side to the bottom side and solder here. Pay atten-
tion to not damage the insulations of single wires while soldering
another.
Non insulated: Shielding
Yellow:
T1
Black:
D
Orange/Green: +B
Red:
GND
Brown/Blue:
T0
Especially watch out not to violate the insulation of the single
wires. The Shield (“Schirm”) must never get in contact with other
pins (e.g. pins of the push buttons).
Finally the cable is fixed on the PCB using the cable strap. The
cable strap must be tightened in a way that a reliable strain relief is
granted. The end of the cable strap must be on the top side of the
PCB (
see image on the following page
).
Component layout diagram on the PCB
Populated PCB
8. Verification and mounting the PIC
After soldering all components on the PCB verify once more that
they are placed according component layout diagram and that they
are oriented properly. Check that all solder points on the bottom
side of the PCB look correct. Note especially if there are any un-
desired solder bridges between solder pads.
After verification the PIC can be mounted (Notch to R8).
9. Preparing the top case part
The case is to be drilled at several places. To do so, use the drill-
ing template printed on the very last page of these instructions and
work very carefully. The PCB might not fit the case properly when
to big tolerances occur.
The case top is the flat one of the two case parts.
1. Cut out the drilling template (see below) precisely.
2. Lay the drilling template into the inner side of the case top part
and fix it e.g. by some scotch at the four edges.
3. Use a needle to mark drill holes.
4. Scratch the display frame with a sharp tool.
5. Check not to have forgotten any drill hole.
6. Dismantle scotch and drill mask.
