ELENCO SP-3B Solder Practice Kit Instruction Manual
- October 30, 2023
- ELENCO
Table of Contents
SP-3B Solder Practice Kit
SOLDER PRACTICE KIT – MODEL SP-3B
The Solder Practice Kit is designed to help users learn and
practice soldering skills. The kit includes various parts, such as
resistors, capacitors, semiconductors, and miscellaneous materials.
The kit also includes an assembly and instruction manual for easy
setup and usage.
Product Parts List
The following is a list of parts included in the Solder Practice
Kit:
-
Resistors: 2 R1, R7; 2 R2, R8; 2 R3, R9; 2 R4, R10; 2 R5, R11;
1 R13; 1 R14; 1 R15; 1 R16; 2 R6, R12; 1 R17; 1 R18; 1 R19; 1
R20 -
Capacitors: 2 C1, C2
-
Semiconductors: 2N3904 Transistor NPN; Red LED (Light Emitting
Diode) -
Miscellaneous: PC board, SW1 Slide switch, Desoldering wick,
Battery snap, U1 16-pin IC socket, Wire 22AWG solid, Color code
calculator, Lead-free solder tube
Product Usage Instructions
Before using the Solder Practice Kit, ensure that all parts are
included and undamaged. If any parts are missing or damaged,
contact the instructor or support@elenco.com for assistance.
Refer to the assembly and instruction manual included with the
kit for step-by-step setup and usage instructions.
When using the kit, follow these general guidelines:
-
Handle all parts with care to avoid damage
-
Use appropriate tools and safety equipment, such as soldering
iron and goggles -
Refer to the resistor reading exercise on page 7 of the manual
to familiarize yourself with resistor color band coding -
Identify capacitor values by their capacitance value in pF
(picofarads), nF (nanofarads), or mF (microfarads). Refer to the
manual for further guidance -
Use lead-free solder tube provided in the kit for
soldering -
After completing the soldering exercise, test the circuit to
ensure proper functionality
WARNING: This product contains chemicals known to the State of
California to cause cancer and reproductive harm. For more
information, visit www.P65Warnings.ca.gov.
SOLDER PRACTICE KIT
MODEL SP-3B
Assembly and Instruction Manual
WARNING: Cancer and Reproductive Harm www.P65Warnings.ca.gov.
Copyright © 2023, 2001 by Elenco® Electronics, LLC. All rights reserved.
Revised 2023 REV-P
753000
No part of this book shall be reproduced by any means; electronic, photocopying, or otherwise without written permission from the publisher.
PARTS LIST
If you are a student, and any parts are missing or damaged, please see
instructor or bookstore. If you purchased this kit from a distributor,
catalog, etc., please contact us at support@elenco.com for additional
assistance, if needed. DO NOT contact your place of purchase as they will not
be able to help you.
RESISTORS
Note: Please refer to page 7 for the resistor reading exercise. This will familiarize you with the resistor color
band coding.
Qty. Symbol r 2 R1, R7 r 2 R2, R8 r 2 R3, R9 r 2 R4, R10 r 2 R5, R11 r 1 R13 r 1 R14 r 1 R15 r 1 R16 r 2 R6, R12 r 1 R17 r 1 R18 r 1 R19 r 1 R20
Value 100W 5% 1/4W 150W 5% 1/4W 200W 5% 1/4W 220W 5% 1/4W 330W 5% 1/4W 18kW 5% 1/4W 27kW 5% 1/4W 39kW 5% 1/4W 47kW 5% 1/4W 56kW 5% 1/4W 100kW 5% 1/4W 120kW 5% 1/4W 470kW 5% 1/4W 680kW 5% 1/4W
Color Code brown-black-brown-gold brown-green-brown-gold red-black-brown-gold red-red-brown-gold orange-orange-brown-gold brown-gray-orange-gold red-violet- orange-gold orange-white-orange-gold yellow-violet-orange-gold green-blue- orange-gold brown-black-yellow-gold brown-red-yellow-gold yellow-violet- yellow-gold blue-gray-yellow-gold
Part # 131000 131500 132000 132200 133300 151800 152700 153900 154700 155600 161000 161200 164700 166800
Qty. Symbol r 2 C1, C2
Value 10mF 16V
CAPACITORS Description Electrolytic
Part # 271015
Qty. Symbol r 2 Q1, Q2 r 2 LED1, LED2
Qty. r 1 r 1 r 1 r 1 r 1 r 1 r 1 r 1
SEMICONDUCTORS
Value
Description
2N3904
Transistor NPN
Red
LED (Light Emitting Diode)
MISCELLANEOUS
Symbol
Description
PC board
SW1
Slide switch
Desoldering wick
Battery snap
U1
16-pin IC socket
Wire 22AWG solid
Color code calculator
Lead-free solder tube
Part# 323904 350002
Part # 517042 541102 556000 590098 664016 834064 9CC100
9LF99
PARTS IDENTIFICATION
Resistor
Capacitor Semiconductors
Miscellaneous
Battery Snap
Electrolytic
LED Transistor IC Socket 16-pin
-1-
Solder Wick
Slide Switch Solder
IDENTIFYING RESISTOR VALUES
Use the following information as a guide in properly identifying the value of
resistors.
BAND 1
1st Digit
Color Digit
Black 0
Brown 1
Red
2
Orange 3
Yellow 4
Green 5
Blue
6
Violet 7
Gray
8
White 9
BAND 2
2nd Digit
Color Digit
Black 0
Brown 1
Red
2
Orange 3
Yellow 4
Green 5
Blue
6
Violet 7
Gray
8
White 9
Multiplier
Color Black Brown Red Orange Yellow Green Blue Silver Gold
Multiplier
10 100 1,000 10,000 100,000 1,000,000 0.01 0.1
Resistance
Tolerance
Color Tolerance
Silver
±10%
Gold
±5%
Brown ±1%
Red
±2%
Orange ±3%
Green ±0.5%
Blue
±0.25%
Violet
±0.1%
12
BANDS
Multiplier Tolerance
IDENTIFYING CAPACITOR VALUES
Capacitors will be identified by their capacitance value in pF (picofarads), nF (nanofarads), or mF (microfarads). Most capacitors will have their actual value printed on them. Some capacitors may have their value printed in the following manner. The maximum operating voltage may also be printed on the capacitor.
Electrolytic capacitors have a positive and a negative electrode. The negative lead is indicated on the packaging by
For the No. Multiplier Multiply By
01234589 1 10 100 1k 10k 100k .01 0.1
a stripe with minus signs and possibly
2A222J
100V
arrowheads. Also, the negative lead of a radial electrolytic is shorter than
the positive one.
Warning:
If the capacitor is
CERAMIC DISC
Second digit First digit
101K
50V
Multiplier Tolerance*
MYLAR
Tolerance* Multiplier
Second digit First digit
connected with
incorrect polarity, it may heat up and either leak, or cause the capacitor to explode.
Polarity marking
()
Maximum working voltage (may or may not appear on the cap)
The value is 10 x 10 = 100pF, +10%, 50V
The value is 22 x 100 = 2,200pF or .0022mF, +5%,100V
(+)
() (+)
Axial
Radial
The letter M indicates a tolerance of +20% The letter K indicates a tolerance of +10% The letter J indicates a tolerance of +5%
Note: The letter “R” may be used at times to signify a decimal point; as in 3R3 = 3.3
METRIC UNITS AND CONVERSIONS
Abbreviation p n m m k M
Means Pico nano micro milli unit kilo mega
Multiply Unit By .000000000001
.000000001 .000001 .001 1 1,000 1,000,000
Or 10-12 10-9 10-6 10-3 100 103 106
-2-
1. 1,000 pico units = 1 nano unit
2. 1,000 nano units = 1 micro unit
3. 1,000 micro units = 1 milli unit
4. 1,000 milli units = 1 unit
5. 1,000 units
= 1 kilo unit
6. 1,000 kilo units = 1 mega unit
CONSTRUCTION
Introduction The most important factor in assembling your SP3B Solder Practice
Kit is good soldering techniques. Using the proper soldering iron is of prime
importance. A small pencil type soldering iron of 25 – 40 watts is
recommended. The tip of the iron must be kept clean at all times and well
tinned.
Solder For many years leaded solder was the most common type of solder used by
the electronics industry, but it is now being replaced by lead-free solder for
health reasons. This kit contains lead-free solder, which contains 99.3% tin,
0.7% copper, and has a rosinflux core. Lead-free solder is different from lead
solder: It has a higher melting point than lead solder, so you need higher
temperature for the solder to flow properly. Recommended tip temperature is
approximately 700OF; higher temperatures improve solder flow but accelerate
tip decay. An increase in soldering time may be required to achieve good
results. Soldering iron tips wear out faster since lead-free solders are more
corrosive and the higher soldering temperatures accelerate corrosion, so
proper tip care is important. The solder joint finish will look slightly
duller with lead-free solders.
Use these procedures to increase the life of your soldering iron tip when
using lead-free solder:
· Keep the iron tinned at all times.
· Use the correct tip size for best heat transfer. The conical tip is the most
commonly used.
· Turn off iron when not in use or reduce temperature setting when using a
soldering station.
· Tips should be cleaned frequently to remove oxidation before it becomes
impossible to remove. Use Dry Tip Cleaner (Elenco® #SH-1025) or Tip Cleaner.
If you use a sponge to clean your tip, then use distilled water (tap water has
impurities that accelerate corrosion).
Solder
Rosin Core
Figure 1
Safety Procedures
· Always wear safety glasses or safety goggles to protect your eyes when
working with tools or soldering iron, and during all phases of testing.
· Be sure there is adequate ventilation when soldering.
· Locate soldering iron in an area where you do not have to go around it or
reach over it. Keep it in a safe area away from the reach of children.
· Do not hold solder in your mouth. Solder is a toxic substance. Wash hands
thoroughly after handling solder.
Flux Most solder contains flux in the hollow core of the solder allowing it to be applied automatically when you heat the solder. The flux will remove any oxide film on the metals soldered creating a good metalto-metal contact. This is called “wetting the metal”. There are three types of solder fluxes: chloride, organic and rosin. In the electronics industry, only the rosin type is used. Rosin flux comes in two types, pure and active. The most reliable is the pure type, since it doesn’t cause dendrites between tracks on the PC board as the active type does. Due to the highly corrosive and moisture attracting characteristics of the chloride and organic type fluxes, they should not be used in electronics.
Surface Preparation In order for the solder to adhere to the connection, the metals must be clean and free of nonmetallic materials. Flux in the solder can remove oxides from metal but not other materials like dirt or grease. To remove these, use a small steel brush or fine emery cloth.
Mechanical Connection When all the surfaces are clean, the metals should have a solid mechanical connection. Wires should be tightly wrapped around each other or to the terminal. This will eliminate large gaps that create weak solder joints. Solder should not be used as a mechanical connection.
Terminal
Solder
Wire
Figure 2 -3-
Types of Soldering Devices A number of different types of soldering devices: irons, guns and stations are available today. Irons are used for light to medium work and guns are for medium to heavy-duty work. The station type can range from light to heavy-duty For working on PC boards, irons ranging from 15 to 40 watts are suitable, or a station with a range of 15 to 40 watts. If you use an iron with a higher wattage rating than 40 watt, you may damage the copper tracks on the PC board. The higher wattage irons are best suited for heavy-duty electrical jobs.
Soldering Iron
Soldering Gun
Soldering Station
Solder Tips The tip is the very important part of the iron. The material that the tip is made from is an essential factor. The soldering iron tip contains four different metals as shown in Figure 3. The core consists of copper. Since the copper is a soft material, it is plated with iron. Chrome plating is used on the area where no soldering takes place to prevent oxidation. Then the tip is plated with tin, because it can be easily cleaned.
Tin Plating
Chrome Plating Iron Plating Copper
Tip Cleaning A good clean solder tip makes soldering much easier. The tip
should be tinned by lightly coating it with solder to prevent it from
oxidizing. The tip can become pitted (black spots) from normal use. It is
important to clean the tip by wiping it with a wet sponge or rag. For tips
that need a good cleaning, the tip tinner and cleaner should be used. Never
use a file or abrasive material to clean the tip. Using such methods will
damage the plating and ruin the tip. Do not remove the excess solder from the
tip before storing. The excess solder will prevent oxidation.
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.
Figure 3
Today, tips are manufactured in a variety of different shapes (see figure
below). The chisel shape is one of the most common. Having a choice of tip
styles allows you to choose the one best suited for your soldering needs. Due
to the high heat, removable tips can bond themselves to the heating element if
left in place for extended periods of time. Periodic removal of the tip is
therefore advisable.
Desoldering Tool
Desoldering Bulb
Solder Wick
1/32″
1/64″
1/16″
1/8″
3/64″
Desoldering Station
-4-
SOLDER PRACTICE
Double Pads Before we begin to assemble and solder the components to the
solder practice PC board, we will start first by practice soldering to the
double pads on the edge of the PC board (see Figure 4). Figure 4
1. Apply a small amount of solder to the iron tip. This allows the heat to leave the iron and onto the foil.
2. Place the iron on the top half of pad and then apply the solder (see Figure 5). Allow the solder to flow around the pad. Then, remove the solder and the iron and let the solder cool. The solder should be neat and smooth.
3. Repeat step 2 on the bottom half of the pad (see Fig. 5).
4. Practice again on the second large pad.
Solder
Soldering Iron
Tack Soldering You will make 10 tack solder connections by soldering five wires to the top row of pads.
1. Cut 5 one-inch wires and strip 1/8″ insulation off both ends.
2. Place the iron and the wire on top left pad as shown in Figure 7. Allow the solder to flow around the wire. Then, remove the iron and let the solder cool. You may need to add some more solder. The solder should be neat and smooth.
3. Pull the wire to make sure you have a good solder joint.
4. Bend the wire and solder it to the next pad, as shown in Figure 7.
5. Now solder the remaining wires to the pads as
shown in Figure 7.
Soldering Iron
Solder
Figure 5 Single Pads Now practice using the single pads. Start with the four
square pads and use the same soldering procedures as the large pads. Note that
the spacing between the pads decrease as the pads get smaller. Be sure there
are no solder bridges between the pads.
Solder Bridge Solder bridges occur when solder runs between circuit paths and
creates a short circuit. This is usually caused by using too much solder. Try
to intentionally make a solder bridge on each section (see Figure 6). Then,
remove it by simply dragging your soldering iron across the solder bridge as
shown. It is best to wipe the iron tip with a wet sponge to remove the solder.
You can also use solder wick as described on page 7.
Figure 7 Jumper Wires In this section, you will solder 20 jumpers between the
two rows of holes.
1. Cut a one-inch wire and strip 1/8″ insulation off both ends.
2. Insert the wire between the top and bottom hole (see Figure 8a).
3. Apply a small amount of solder to the tip. Immediately apply solder to the
opposite side of the connection, away from the iron. Allow the heated wire and
circuit foil to melt the solder (see Figure 8b).
4. Cut off the excess leads.
5. Solder the remaining 19 jumper wires.
Figure 6
PC Board Solder Bridges
Soldering Iron
Jumper Wires
Soldering Iron
Solder
Drag Iron
Figure 8a -5-
Figure 8b
PC BOARD REPAIR
Hairline Cracks The hairline cracks can develop in the copper foil if the PC
board is flexed. This can be easily repaired by making a solder bridge across
the two foils. The solder should smoothly flow across the foil as shown in
Figure 9. If the solder does not adhere to the foil, it will sit on the foil
as a blob as shown if Figure 10.
Solder Foil
Figure 9
Figure 10
1. Make five solder bridges using the second row of single pads, starting from the left side (see Figure 11). Solder Bridges
Figure 11
Reinforcing a Repair A solder bridge repair can be reinforced using a solid
wire. Now add a wire to the five solder bridges you just made. 1. Strip a 1/2″
of insulation off one end of the wire
and then tin it. 2. Hold the tinned wire on top of the solder bridge. 3. Place
the iron on the wire until the solder melts. 4. Remove the iron while holding
the wire in place
against the foil. Make sure the wire does not move until the solder hardens.
5. Check for a good solder connection. 6. Cut the wire off as close to the
solder joint as possible.
7. Practice this procedure four more times.
Wide Gaps Wide gaps in the copper foil can be bridged using a small wire
soldered across the gaps (see Figure 12). Four wires will be soldered across
the two rows of small solder pads.
Board Bare Wire Solder Foil
Figure 12
1. Place the iron on the top of a pad and then apply the solder (see Figure
12). Allow the solder to flow around and form a small pool.
2. Repeat Step 1 on the adjacent pad. 3. Strip 1/2″ of insulation off one end
of the wire and
then tin it. 4. Position the wire on top of the solder pad and then
place the iron on the wire. As the solder melts, the wire will be pressed down
against the pad (see Figure 12). Remove the iron while holding the wire in
place. Make sure the wire does not move until the solder hardens. 5. Check for
a good solder connection. 6. Repeat step 4 on the adjacent pad. 7. Cut the
wire off as close to the solder joint as possible (see Figure 12). 8. You can
hold the wire down with a screwdriver and resolder if needed. 9. Practice this
procedure three more times on the remaining pads.
-6-
REMOVING EXCESS SOLDER USING DESOLDERING WICK
Desoldering wick is a braided wire coated with noncorrosive rosin flux. It is
the simplest and safest tool for removing solder from a solder connection.
When the braided wire is heated, the flux cleans and breaks up the surface
tension so the melted solder from the connection flows into the braid by
capillary action.
Included in this kit is a six inch length of solder wick (desoldering braid).
Soldering Iron Tip
CAUTION: Wick gets HOT – use long nose pliers to hold wick.
Foil Side of PC board
Desoldering Wick
Using the Desoldering Wick
1. Place the wick against the solder with the tip of a hot soldering iron
(see Figure 13).
2. The molten solder is sucked up into the wick by capillary action.
3. When the iron and wick are removed, the solder should be removed. You need
to repeat the process if some solder remains.
If necessary, repeat the procedure until all of the unwanted solder is
removed.
After the excess solder has been removed, clip off and discard the solder-
saturated portion of the braid. For best results, always use a fresh area of
the braid for each procedure.
Excess Solder
Using desoldering wick to remove excess solder. Figure 13
A close-up view of the accumulation of solder onto the solder wick
(desoldering braid).
Figure 14
RESISTOR READING EXERCISE
Before starting assembly of your solder practice project, you should be
thoroughly familiar with the 4-band color code system. Many of the resistor
values will be identified by color bands and it is easy to mistake their value
if you read the colors incorrectly or read the value from the wrong end. Do
the following exercise in resistor values. Place your answer in the box
beneath the resistor. Answers are on the bottom of this page.
(1) brown-green-red-gold
(2) brown-black-orange-gold
(3) brown-black-yellow-gold
(4) red-red-orange-gold
(5) yellow-violet-brown-gold
(6) blue-gray-orange-gold
(7) yellow-violet-black-gold
(8) brown-blue-brown-gold
(9) orange-orange-red-gold
(10) green-brown-red-gold
(11) brown-black-green-gold (12) brown-gray-orange-gold
Answers to Resistor Reading Exercise: 1) 1.5kW+5%; 2) 10kW+5%; 3) 100kW+5%; 4) 22kW+5%; 5) 470W+5%; 6) 68kW+5%; 7) 47W+5%; 8) 160W+5%; 9) 3.3kW+5%; 10) 5.1kW+5%; 11) 1MW+5%; 12) 18kW+5%
-7-
THEORY OF OPERATION
The solder practice kit consists of a circuit oscillating at one hertz (one
cycle per second). The oscillator consists of two transistors Q1 and Q2, and
resistors, R1 – R11 and capacitors C1 and C2. This configuration is known as a
multivibrator circuit.
When voltage is first applied to this multivibrator circuit, one transistor
(possibly Q1) will conduct faster, causing transistor Q2 to stay off. Q1 will
continue to conduct until it saturates. At this point,
Q2 will start to conduct, causing Q1 to rapidly cutoff. This process continues alternately causing Q1 or Q2 to conduct. The output will be a square wave. The frequency is determined by the time constants of resistor R6 and capacitor C1, also R12 and C2. Two LED diodes are placed in the collectors of the transistors and will light when current is passing through them. Resistors R1 – R5, R7 -R11 determine the current passing through the LEDs.
SCHEMATIC DIAGRAM
-8-
SOLDERING COMPONENTS TO THE PC BOARD
A poorly soldered joint can greatly affect small current flow in circuits and
can cause equipment failure. You can damage a PC board or a component with too
much heat or cause a cold solder joint with insufficient heat. Sloppy
soldering can cause bridges between two adjacent foils preventing the circuit
from functioning.
Safety Procedures
· Wear eye protection when soldering. · Locate soldering iron in an area where
you do not have to go around it or reach over it. · Do not hold solder in your
mouth. Wash your hands thoroughly after handling solder. · Be sure that there
is adequate ventilation present.
What Good Soldering Looks Like
A good solder connection should be bright, shiny, smooth, and uniformly flowed
over all surfaces.
Soldering a PC board
1. Solder all components from the copper foil side only. Push the soldering
iron tip against both the lead and the circuit board foil.
Soldering Iron Component Lead
Foil
Circuit Board
2. Apply a small amount of solder to the iron tip. This allows the heat to
leave the iron and onto the foil. Immediately apply solder to the opposite
side of the connection, away from the iron. Allow the heated component and the
circuit foil to melt the solder.
Solder
Soldering Iron
Foil
Types of Poor Soldering Connections
1. Insufficient heat – the solder will not flow onto the lead as shown.
Rosin
Soldering iron positioned incorrectly.
2. Insufficient solder – let the solder flow over the connection until it is
covered. Use just enough solder to cover the connection.
Solder
Gap Component Lead
3. Excessive solder – could make connections that you did not intend to
between adjacent foil areas or terminals.
Solder
3. Allow the solder to flow around the connection. Then, remove the solder and the iron and let the connection cool. The solder should have flowed smoothly and not lump around the wire lead.
Solder
Soldering Iron
Foil
4. Here is what a good solder connection looks like.
Heat Sinking
Electronic components such as transistors, IC’s, and diodes can be damaged by
the heat during soldering. Heat sinking is a way of reducing the heat on the
components while soldering. Dissipating the heat can be achieved by using long
nose pliers, an alligator clip, or a special heat dissipating clip. The heat
sink should be held on the component lead between the part and the solder
joint.
Soldering Iron
Solder
PC Board
-9-
Heat Sink
(this can be ordered as part of Elenco’s Solder Ease Kit Model SE-1).
Heat Sensitive Component (Diode)
PC BOARD ASSEMBLY
Solder the following parts to the PC board.
J2 – Jumper Wire (see Fig. A)
J1 – Jumper Wire (see Fig. A)
J5 – Jumper Wire (see Fig. A)
J4 – Jumper Wire (see Fig. A)
R1 – 100W 5% ¼W Resistor (brown-black-brown-gold)
(see Figure B)
R2 – 150W 5% ¼W Resistor (brown-green-brown-gold)
(see Figure B)
R3 – 200W 5% ¼W Resistor (red-black-brown-gold) (see Figure B)
R4 – 220W 5% ¼W Resistor (red-red-brown-gold) (see Figure B)
Figure A
Cut a 1″ wire and strip 1/8″ of insulation off of both ends.
J3 – Jumper Wire (see Fig. A) J6 – Jumper Wire (see Fig. A) R10 – 220W 5% ¼W
Resistor
(red-red-brown-gold) (see Figure B)
R9 – 200W 5% ¼W Resistor (red-black-brown-gold) (see Figure B)
R8 – 150W 5% ¼W Resistor (brown-green-brown-gold)
(see Figure B) R7 – 100W 5% ¼W Resistor (brown-black-brown-gold)
(see Figure B)
Figure B
Mount the resistor flat against the PC board as shown.
Resistance Testing #1 (If you do not have a meter, continue to page 11) You will test the solder connections by measuring the resistance from the following points. If your readings are different, double check your soldering connections.
Location Point A (left side of J1) to point B (right side of J3) Point A (left side of J1) to point C (top lead of R4) Point D (left side of J4) to point E (right side of J6) Point D (left side of J4) to point F (top lead of R10)
Value
0.1 – 1W 670W +5% 0.1 – 1W +5% 670W +5%
Circuit (J1-J3) (J1-J3, R1-R4) (J4-J6) (J4-J6, R7-R10)
A
D
C
B E F
-10-
PC BOARD ASSEMBLY (continued)
Solder the following parts to the PC board.
U1 – 16-pin IC Socket (see Figure C)
R14 – 27kW 5% ¼W Resistor (red-violet-orange-gold) (see Figure D)
R13 – 18kW 5% ¼W Resistor (brown-gray-orange-gold)
(see Figure D) R17 – 100kW 5% ¼W Resistor (brown-black-yellow-gold)
(see Figure D) R18 – 120kW 5% ¼W Resistor
(brown-red-yellow-gold) (see Figure D)
Figure C
R15 – 39kW 5% ¼W Resistor (orange-white-orange-gold)
(see Figure D) R16 – 47kW 5% ¼W Resistor (yellow-violet-orange-gold)
(see Figure D) R19 – 470kW 5% ¼W Resistor (yellow-violet-yellow-gold)
(see Figure D) R20 – 680kW 5% ¼W Resistor
(blue-gray-yellow-gold) (see Figure D)
Figure D
Notch
When mounting the IC socket, make sure that the notch is in the same direction
as marked on the PC board.
White Circle
Stand resistor on end as shown with the body inside the white circle
Resistance Testing #2 (If you do not have a meter, continue to page 12) Each resistor is connected across two pins of the IC socket. You will test the solder connections by measuring the resistance from the following IC pins. If your readings are different, double check your soldering connections.
Location
R14 – Measure from pin 1 to pin 2 R13 – Measure from pin 3 to pin 4 R17 –
Measure from pin 5 to pin 6 R18 – Measure from pin 7 to pin 8 R19 – Measure
from pin 9 to pin 10 R20 – Measure from pin 11 to pin 12 R16 – Measure from
pin 13 to pin 14 R15 – Measure from pin 15 to pin 16
Value
27kW +/ 5%
1
16
18kW +/ 5%
100kW +/ 5%
120kW +/ 5%
470kW +/ 5%
680kW +/ 5%
47kW +/ 5%
39kW +/ 5%
8
9
-11-
PC BOARD ASSEMBLY (continued)
Solder the following parts to the PC board.
R6 – 56kW 5% ¼W Resistor (green-blue-orange-gold)
(see Figure B)
R5 – 330W 5% ¼W Resistor (orange-orange-brown-gold)
(see Figure B)
C1 – 10mF 16V Electrolytic (see Figure E)
Battery Snap (see Figure F)
SW1 – Switch SPST
LED1 – Red LED (see Figure G)
Q1 – 2N3904 Transistor (see Figure H)
R12 – 56kW 5% ¼W Resistor (green-blue-orange-gold)
(see Figure B)
R11 – 330W 5% ¼W Resistor (orange-orange-brown-gold)
(see Figure B)
C2 – 10mF 16V Electrolytic (see Figure E)
LED2 – Red LED (see Figure G)
Q2 – 2N3904 Transistor (see Figure H)
J7 – Jumper Wire (see Figure A)
Figure E
Electrolytic capacitors have polarity. Be sure to mount them with the negative
() lead (marked on side) in the correct hole.
Polarity Mark
() (+)
Figure F
Thread the battery snap wires through the hole in the PC board from the solder
side as shown. Solder the red wire to the (+) point and the black wire to the
() point on the PC board.
Red
Black
Figure G
Mount the LED onto the PC board with the flat side of the LED in the same
direction as marked on the PC board.
Mount flush with PC board
Flat
Warning: If the capacitor is connected with incorrect polarity, it may heat up and either leak or cause the capacitor to explode.
Figure H
Mount the IC with the flat side in the same direction as marked on the PC
board. Solder and cut off the excess leads.
Flat
OPERATION
Connect a 9 volt battery to the battery snap. Turn the ON/OFF switch to the ON
position and the LEDs should alternately light.
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TROUBLESHOOTING
If you are a student, and any parts are missing or damaged, please see
instructor or bookstore. If you purchased this solder practice kit from a
distributor, catalog, etc., please contact Elenco® Electronics
(address/phone/e-mail is at the back of this manual) for additional
assistance, if needed.
If you are experiencing a problem, first read the theory of operation to
familiarize yourself with the operation.
Component Check 1. Be sure that all components have been mounted
in their correct places.
2. Make sure that C1 and C2, the electrolytic capacitor is mounted correctly.
The negative lead should be in the hole as shown on the top legend.
3. Have LEDs LED1 and LED2 been installed correctly? The flat side of their
bodies should be in the same direction as marked on the top legend. If the
LEDs are in backwards, they will not light.
4. Pay close attention to the red and black wires of the battery snap. The
red wire should be installed in the positive (+) hole and the black wire in
the negative () hole. Snap in a fresh 9-volt battery.
Problems 1. No LEDs Light
· Check the solder connections for the battery wires and switch.
· Check that all parts are in the correct way.
2. LED1 Does Not Light · Check C1, LED1 and Q1.
3. LED2 Does Not Light · Check C2, LED2 and Q2.
4. LED1 or LED2 is Always On · Check C1 and C2 for opens. · Check Q1 and Q2
for shorts.
WORD GLOSSARY
Capacitor
An electrical component that can store electrical pressure (voltage) for periods of time.
Cold Solder Joint
Occurs because insufficient heat was applied or the connection was moved before the solder had set. Connection looks crystalline, crumbly, or dull.
Flux
A substance that is used to cleanse the surface of oxide before it is soldered. Always used in electronics work. Most of the solder used in electronics has flux built right into it.
Heat Sinking
A process of keeping the component from becoming overheated during soldering. Any metal object that can be clamped to the component lead will work as an effective heat sink. An alligator clip or pliers work well.
Integrated Circuit (IC) A type of circuit in which transistors, diodes, resistors, and capacitors are all constructed on a semiconductor base.
Jumper Wire
A wire that is connected from one place to another on a PC board, thereby making a connection between two pads.
LED
Common abbreviation for light emitting diode.
Light Emitting Diode A diode made from gallium arsenide that has a turn-on energy so high that light is generated when current flows through it.
Oxidation
Most metals, when exposed to air, form an oxide on their surface which prevents solder from adhering to the metal.
Polarity
The division of two opposing forces or properties.
Printed Circuit Board
A board used for mounting electrical components. Components are connected using metal traces “printed” on the board instead of wires.
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WORD GLOSSARY (continued)
Resistor
Component used to control the flow of electricity in a circuit. It is made of carbon.
Rosin Core Solder
The most common type of solder used in electronics generally referred to as 63/37 rosin core solder.
Solder
A tin/lead alloy that melts at a very low temperature, used to join other metals together. It produces excellent electrical connections.
Solder Bridge
An unwanted solder connection between two points that are close together.
Solder Melting Point The temperature at which a tin/lead alloy (solder) melts. The common solder used in electronics (63% tin / 37% lead) has a melting point of 361OF.
Solder Wick
Braided wire coated with flux to effectively remove solder from a connection.
Soldering
The process of joining two or more metals by applying solder to them.
Tack Soldering
A connection where the lead or wire does not have any mechanical support.
Tinning the Tip
A process of coating the soldering iron tip with solder to minimize the formation of oxide on the tip, which would reduce the amount of heat transfer.
Transistor
An electronic device that uses a small amount of current to control a large amount of current.
Wire Gauge
Refers to the size of the wire. The bigger the number, the smaller the diameter of the wire. 18 gauge to 24 gauge is generally used for hook-up in electronics.
QUIZ
1. The solder supplied is comprised of what two materials? r A. Gold and
copper r B. Tin and copper r C. Zinc and copper r D. Lead and aluminum
2. What type of flux should be used in electronics? r A. Chloride r B.
Organic r C. Rosin r D. Corrosive
3. When working on PC boards, what wattage range of iron is ideal? r A. 15-40
watts r B. 50-100 watts r C. 1-10 watts r D. 100-200 watts
4. Tinning the soldering tip will prevent it from . . . r A. heating. r B.
melting. r C. soldering. r D. oxidizing.
5. Proper solder adhesion requires that the metal surface to be . . . r A.
solder free. r B. clean. r C. greasy.
r D. cold.
6. Solder wick is used to . . . r A. remove solder. r B. solder in small
parts. r C. cleaning the soldering iron tip. r D. removing flux.
7. A cold solder joint is caused by . . . r A. a solder bridge. r B. using
60/40 solder. r C. insufficient heat. r D. acid core solder.
8. When two adjacent solder joints accidentally touch, it is called . . . r
A. a jumper. r B. a blob. r C. a solder hole. r D. a solder bridge.
9. What ratio has the greatest amount of tin? r A. 20/60 r B. 40/60 r C.
50/50 r D. 93/7
10. A good solder connection should be . . . r A. dull and rough. r B. shiny,
bright and smooth. r C. lumped around the connection. r D. soldered on one
side of the connection.
Answers: 1. B, 2. C, 3. A, 4. D, 5. B, 6. A, 7. C, 8. D, 9. D, 10. B
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