Elenco Solder Practice Kit w/ Iron &amp - Manual (Page 5)

Clean Connections
Proper solder adhesion requires that the metal surface to be free of dirt
and grease. The flux only removes the oxides so a brush or rag can be
used to clean metal. There are contact cleaners in aerosol cans and
other solvents available.
Desoldering
Great care should be taken when repairing or correcting a mistake on a
PC board. The metal foil can be easily pulled up or broken from excessive
heat.
Use the least amount of heat as possible. You can use a
desoldering tool, bulb, wick or a station. These tools will remove the
solder enabling you to correct the problem.
Soldering Components to the PC Board
A. A 15 to 40 watt pencil type soldering iron with a 1/8” or 3/16” pyramid
works well.
B. The soldering iron tip must be kept clean at all times. Wipe it on a wet
sponge or cloth, then tin the entire tip to give it a wet look. This will
prevent the tip from oxidizing.
C. Always use rosin core solder, type 60/40 (60% tin, 40% lead). Never
use acid core solder, for it will damage the components.
-4- -7-
Circuit Board Assembly
Note that electrolytic capacitors, transistors, LEDs and the IC must be
installed according to their polarity. Refer to Figure 1 for identification.
Figure 3
After completing the assembly of the kit, double back to see that the
soldering looks good and all of the components are in their proper place.
If everything is all right, attach the 9V battery to the battery snap. The
LEDs should alternately light and the speaker should sound a wobbling
siren.
Battery Snap
C5 - .02 µF or .022µF
Discap
C6 - 100 µF Lytic
Note polarity
IC1 555 or 1455
Note dot marking
6” Wires (strip 1/4”
off of both ends)
VR1 200 Ω
Volume Control
(these holes not used)
R3 - 68 Ω Resistor
(blue-gray-blk-gold)
R2 - 1k Ω 1/2W
(brn-blk-red-gold)
C2 - 10 µF Lytic
Note polarity
Q1, Q2 - 2N3904
transistors
(note flat)
LED - Note flat
R9 - 10k Ω Resistor
(brn-blk-orange-gold)
R8 - 10k Ω Resistor
(brn-blk-orange-gold)
Jumper Wire, use
cut-off from resistors
R7 - 470 Ω Resistor
(yel-vio-brn-gold)
C3 - 10 µF Lytic
Note polarity
R6 - 56k Ω Resistor
(grn-blue-org-gold)
R5 - 47k Ω Resistor
(yel-vio-org-gold)
C4 - .02 µF or .022µF
Discap
R4 - 56k Ω Resistor
(grn-blue-org-gold)
C1 - 10 µF Lytic
Note polarity
R1 - 470 Ω Resistor
(yel-vio-brn-gold)
Jumper Wire
LED - Note flat
After completing the above assembly, twist the two speaker wires together
and solder to speaker lugs.
Cut 12” wire into two 6” wires.
D. Solder all components from the copper
foil side only. Push the soldering iron tip
against both the lead and the circuit
board foil.
Red
Black
Battery Snap
Desoldering Tool Bulb
Solder Wick Desoldering Station
Component Lead
Soldering Iron
Circuit Board
Foil