Capacitors will be identified by their capacitance value in pF (picofarads), nF (nanofarads), or µF (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.
Second Digit
First Digit
The value is 10 x 1,000 =
10,000pF or .01µF 100V
103K
100V
Multiplier
Multiplier
Tolerance*
Maximum Working Voltage
For the No.01234589
Multiply By1101001k10k 100k .010.1
10µF 16V
Note: The letter “R” may be used at times to
signify a decimal point; as in 3R3 = 3.3
*
The letter M indicates a tolerance of +20%
The letter K indicates a tolerance of +10%
The letter J indicates a tolerance of +5%
-2-
CONSTRUCTION
Introduction
The most important factor in assembling your XK-550K Digital / Analog Trainer 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.
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. Solder contains lead and is a toxic substance. Wash your hands
thoroughly after handling solder.
• Be sure that there is adequate ventilation present.
Assemble Components
In all of the following assembly steps, the components must be installed on the top side of the PC board unless
otherwise indicated. The top legend shows where each component goes. The leads pass through the
corresponding holes in the board and are soldered on the foil side.
Use only rosin core solder of 63/37 alloy.
DO NOT USE ACID CORE SOLDER!
What Good Soldering Looks Like
A good solder connection should be bright, shiny,
smooth, and uniformly flowed over all surfaces.
1.Solder all components from
the copper foil side only.
Push the soldering iron tip
against both the lead and
the circuit board foil.
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.
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.
4.
Here is what a good solder
connection looks like.
Component Lead
Foil
Solder
Foil
Solder
Foil
Soldering Iron
Circuit Board
Soldering Iron
Soldering Iron
Types of Poor Soldering Connections
1. Insufficient heat - the
solder will not flow onto the
lead as shown.
2. Insufficient solder - let the
solderflowoverthe
connectionuntilitis
covered. Use just enough
soldertocoverthe
connection.
3. Excessive solder - could
make connections that you
did not intend to between
adjacentfoilareasor
terminals.
4. Solder bridges - occur
when solder runs between
circuit paths and creates a
short circuit. This is usually
caused by using too much
solder.To correct this,
simply drag your soldering
ironacross the solder
bridge as shown.
Rosin
Soldering iron positioned
incorrectly.
Solder
Component Lead
Solder
Soldering Iron
Foil
Gap
Drag
-3-
INTRODUCTION
The XK-550K Digital/Analog Trainer is divided into four separate kits: BB-550-A, PS-550-B, AN-550-C and DG550D. Each bag of parts is clearly identified. Open only the kit called for in your procedure. DO NOT open any
other bag at this time. The first kit is the BB-550-A which contains only the bredboard. The bredboard will be
assembled to the front panel of the trainer during the assembly of the PS-550-B Power Supply. Read your
instructions carefully.
Power Supply
The XK-550K has five built-in power supplies which will satify most design needs. This includes two variable
power supplies giving up to +20 volts and –20 volts at .5 amp. Below 15V, the current availableis 1 amp. Three
fixed power supplies give you +12VDC, –12VDC or +5VDC at 1 amp each. These fixed voltages are the most
commonly used voltages for design work. All supplies are regulated to within 150mV. This means that you can
increase the current draw from no load to 0.5 amp and the voltage will change less than 150mV. All supplies
are also short circuit protected by using integrated circuit regulator devices.
Analog Trainer Section Function Generator
The analog trainer contains a complete function generator capable of producing sine, square and triangle
waveforms. The frequency of the generator is continuously variable from one hertz to over 100,000 hertz in five
steps. A fine tuning control makes the selection of any frequency easy. The output voltage amplitude is variable
between 0 to 15Vpp. The output impedance is approximately 330 ohms.
Digital Trainer Section
The digital trainer has the necessary functions to do your digital experiments. They consist of a clock generator,
two no-bounce switches, eight LED indicator lamps and eight data switches.
POWER SUPPLY SPECIFICATIONS
Power Supplies:
• +1.25V to 20VDC @ 0.5 amp (1.25V to 15V @ 1 amp).
• –1.25 to -20VDC @ 0.5 amp (–1.25V to –15V @ 1 amp).
• +12V +5% @ 1 amp.
• –12V +5% @ 1 amp.
• +5V +5% @ 1 amp.
• 30VAC center tapped @ 1 amp.
• Load regulation - all DC supplies less than 0.2V no load to 0.5A.
• Line regulation - all DC supplies less than0.2V 105 to 135V.
• Hum and ripple - all DC supplies less than 0.01V RMS.
• Short protection - all DC supplies-internal IC thermal cutoff.
• Fuse 1.25A 250V.
Variable Resistance (undedicated):
• 1kΩ Potentiometer
• 100kΩ Potentiometer
USERS DESCRIPTION OF FRONT PANEL CONTROLS
1) On/Off Switch - Allows power to be applied to all outputs. Switch will
light when on.
2) Fuse Holder - Easy access for replacement of 1.25A fuse.
3) Power Output Terminals - This provides 30VAC center tapped at
15 VAC; also provides output terminal for positive and negative
variable voltages.
4) Variable PositiveVoltage Control - Varies positive voltage from 1.25
to 20V at indicated output connector pin.
5) Variable Negative Voltage Control - Varies negative voltage from
–1.25V to –20V at indicated output connector pin.
6) Power Output Bredblox - Output terminals for GND, –12, +12, and +5.
7) Output terminals for 1k and 100k undedicated potentiometers.
8) 1kΩ undedicated potentiometer.
9) 100kΩ undedicated potentiometer.
89
7
6
5
4
3
2
1
-4-
INSTALL COMPONENTS TO PC BOARD
Start Here
S1 - 5-Pin Connector
(see Figure A)
L-Bracket
(see Figure B)
VR4 - 100kΩ Pot
VR3 - 1kΩ Pot
(see Figure C)
S3 - 3-Pin Connector
S2 - 3-Pin Connector
(see Figure A)
L-Bracket
(see Figure B)
C8 - 0.1µF Mylar (104)
(see Figure D)
Bottom Left Corner of PC Board
Top Left Corner of PC Board
Figure A
Mount the connector as shown and solder the
pins of the connector.
PC Board
Figure B
Note:One side of the
bracket is longer. Mount
this side to the PC board.
Mount the bracket to the
top legend side of the PC
board with a 4-40 x 1/4”
screw and fiber washer.
Top Legend
Side of
PC Board
Fiber
Washer
4-40 x 1/4”
Screw
Figure C
Cut off tab
Mount down flush withPCboard. The
value may be marked on the on the
back side of pot.
Cut off excess lead length after
soldering.
Figure D
Bend the capacitor at a 45
angle before soldering. Cut off
excess leads.
O
-5-
INSTALL COMPONENTS TO PC BOARD
Start Here
C11 - 100µF 25V
(see Figure E)
R1 - 120Ω 5% 1/4W Resistor
(brown-red-brown-gold)
C6 - .1µF Mylar (104)
(see Figure D)
J28 - Jumper Wire
(see Figure F)
J6 - Jumper Wire
(see Figure F)
D12 - 1N4001 Diode
D11 - 1N4001 Diode
(see Figure G)
C14 - 100µF 25V Lytic
C17 - 100µF 25V Lytic
(see Figure E)
C10 - .1µF Mylar (104)
(see Figure D)
Bottom Left Corner of PC Board
R2 - 120Ω 5% 1/4W Resistor
(brown-red-brown-gold)
J2 - Jumper Wire
(see Figure F)
J3 - Jumper Wire
(see Figure F)
These capacitors are polarized. Be
sure to mount them with the “+”
lead in the correct hole as marked
on the PC board.Mount the
capacitor lying flat on the PC board
as shown below.
Figure E
(–)
Figure F
Cut a piece of the #22 bare wire
long enough so that 1/4” of wire
passes through each hole in the
PC board after the wire is formed.
(+)
Figure G
Diodes have polarity. Mount them
with the band as shown on the top
legend.
Hold the bredblock down flush
to the PC board from the top
legend side and solder the
metal pins in place. Then, melt
theplastic pins with your
soldering iron to hold the
plastic blocks in place, as
shown.
Plastic Pins
Melt Pins
-7-
INSTALL COMPONENTS TO PC BOARD
Start HereContinue
C2 - 1000µF 35V Lytic
C4 - 1000µF 35V Lytic
(see Figure J)
C1 - 1,000µF 35V Lytic
C5 - 1,000µF 35V Lytic
(see Figure J)
Figure J
These lytics must be mounted
horizontal to the PC board. Bend
the leads at right angles and then
insert the leads into the PC board
with the negative (–) lead and the
positive (+) lead in the correct holes
as marked on the PC board.
Diodes have polarity. Mount them with
the band as shown on the top legend.
Band
Start Here
C3 - 2200µF Lytic
Mount on foil side of PC board
Note the polarity
(see Figure J)
+
-8-
Top Right Corner
of PC Board
Continue
L-Bracket
(see Figure B)
C7 - .1µF Mylar (104)
(see Figure D)
J5 - Jumper Wire *
(see Figure F)
C9 - .1µF (104) Mylar
(see Figure D)
L-Bracket
(see Figure B)
* Leftover wire will be used in
future sections.
MOUNTING THE PC BOARD
Note: The holes in the two side panels have been punched differently. Be sure that you have the correct side
panel when mounting them to the PC board.
IMPORTANT: Push the PC board up as far as possible before tightening the screws, as shown in Figure La.
Mount the back panel using four 4-40 x 1/4” thread cutting screws (see Figure K).
4-40 x 1/4” Thread
Cutting Screws
Right Side
Left Side
Adjust the PC board
Back Panel
4-40 x 1/4” Thread
Figure K
Cutting Screws
Mount the PC board to the side panels with four 4-40 x 1/4” screws (see Figure L).
Do not tighten the screws.
4-40 x 1/4”
Machine Screws
height with a 4-40 x
1/4” screw
Left Side
Note: From the foil side of the PC board,
inspect the edges to be sure that there
are no component leads shorting against
the side panels.
Top Legend Side
of PC Board
-9-
Right Side
4-40 x 1/4”
Machine Screws
Figure L
Place the top panel onto the unit and align the components with the holes in the top panel. Push the PC board up until
the components come through the top panel and tighten the screws.
Figure La
MOUNT COMPONENTS TOTHE SIDE PANELS
Mount U1, U3 and U5 to the left side panel as shown in Figure N. Insert the pins of each IC into the holes of
the PC board. Then, with the hardware shown in Figure M, attach each IC to the side panel. Solder the pins
of the ICs to the PC board.
U3 - LM7805
U1 - LM317
U5 - LM337
6-32 x 5/16” Screw
Insulator Washer
Side Panel
* Take a small amount of silicone grease from the
packet and apply it with a toothpick onto the back of
the ICs.
* Silicone Grease
6-23 Nut
IC
Mica
Figure M
U3
7805
U1
LM317
Left Side
U5
LM337
-10-
Figure N
ount U2 and U4 to the right side panel as shown in Figure O.
M
Insert the pins of each IC into the holes in the PC board. Then,
with the hardware shown in Figure MA, attach each IC to the
side panel. Solder the pins of the ICs to the PC board.
6-32 x 5/16” Screw
* Silicone Grease
6-23 Nut
U4 - LM7912
U2 - LM7812
Mount the transformer with the black wires as shown in Figure O.
Use the two 8-32 x 3/8” screws, #8 lockwashers, and 8-32 nuts.
Transformer mounted
Figure O
Black Wires
Transformer
#8 Lockwashers
8-32 Nuts
#8-32 x 3/8” Screws
U4
7912
Insulator Washer
Side Panel
IC
Figure MA
*Take asmallamount of silicone grease fromthepacket and
apply it with a toothpick onto the back of the ICs.
Note: Make sure that
the transformer does
not touch U4.
Right Side
U2
7812
Mica
WIRE THE TRANSFORMER TOTHE PC BOARD
Solder the wires to the PC board starting with the top yellow wire as shown in Figure P.
Yellow wire to point F on the PC board
Blue wire to point A on the PC board
Red wire to point C on the PC board
White wire to point E on the PC board
Red wire to point D on the PC board
Blue wire to point B on the PC board
Yellow wire to point G on the PC board
Blue (A)
Blue (B)
Red (C)
Red (D)
White (E)
Yellow (F)
Yellow (G)
Figure P
Yellow (F)
Blue (A)
Red (C)
White (E)
Red (D)
Blue (B)
Yellow (G)
-11-
HOW TO INSTALL CONNECTORS ONTO TRANSFORMER WIRES
connector will be placed onto the primary wires of the transformer. This will allow you to remove the top panel
A
from the trainer. Follow the procedures below.
Cut a six inch length off of each black primary wire.
Strip the insulation off of each end of the six inch wires to expose 1/4” of bare wire.
Place one wire onto the female pin and crimp the outer crimp tabs with pliers over the insulation as shown
in Figure 1A.
Crimp the inner tabs with pliers onto the bare wire as shown in Figure 1B.
Solder the wire to the pin as shown in Figure 1C.
Connect the other female pin to the other wire using the same procedures above.
Insert the two pin/wire assemblies into the female housing as shown in Figure 2. Pull on the wire to check
that the pin is inserted all the way in. It should not pull out of the housing. The locking tabs should be bent
outward to hold the pin in the housing.
Female Pin
Crimp Tab
Locking Tab
Inner
Crimp Tab
SolderOuter
AB
C
Female Housing
Figure 1Figure 2
Transformer Wires
Strip the insulation off of each of the black primary wires to expose 1/4” of bare wire.
Place the wire onto the male pin and crimp the outer crimp tabs with pliers over the insulation as shown in
Figure 3A.
Crimp the inner tabs with pliers onto the bare wire as shown in Figure 3B.
Solder the wire to the pin as shown in Figure 3C.
Connect the other male pin to the other primary wire using the same procedures above.
Insert the two pin/wire assemblies into the male housing as shown in Figure 4. Pull on the wire to check that
the pin is inserted all the way in. It should not pull out of the housing.
Connect the male and female housing as shown in Figure 5. Note that the connector only fits together one way
To detach the connector, push down on the end of the lock arm and pull the two apart.
Male Pin
Crimp Tab
Inner
Crimp Tab
SolderOuter
Male Housing
.
Locking Tab
ABC
Figure 3Figure 4
Lock Arm
Figure 5
-12-
MOUNT COMPONENTS TO PANEL
Push the illuminated switch into the hole in the top
panel with the lugs as shown in Figure Q.
Install the fuse holder with the side lug in the position
shown in Figure Q. Fasten the fuse holder in place
with the nut as shown in Figure Q. Unscrew the cap
and insert the fuse into the holder.
There is a raised area on the back side of the top
panel.Screw the spacer to the raised area by
inserting a 4-40 x 1/4” flat head screw into the hole in
the raised area from the top side of the panel (see
Figure R).
When mounting the bredboard, use the holes shown in
Figure S. Mount the bredboard with two #4 x 1/4” AB
black screws from the back side of the top panel as
shown in Figure R. The negative (blue) stripe should
be on top and the numbers reading from left to right
should start with number 1 (see Figure T). CAUTION:
Do not remove the paper backing from the back of
the bredboards.Do not over-tighten the black
screws.
Back Side - Lower
Right Corner
Illuminated Switch
Top Panel
Plastic Washer
Fuse Holder
Figure Q
Nut
Side Lug
Top Panel
Figure R
Bredboard
Spacer
#4 x 1/4” AB Screws
4-40 x 1/4”
Flat Head
Screw
ON
Figure T
REGULATED
POWER SUPPLY
0
2
+
D
V
15VAC
C
30VAC
–
15VAC
OFF
V
D
0
2
Figure S
C
GND
–12
+12
+5
5
1
j
i
h
g
f
e
d
c
b
a
10
-13-
WIRE SWITCH AND FUSE HOLDER (see Figure U)
Line Cord
Slide the line cord through the back panel as shown.
Spread the three line cord wires apart 6” from the end.
Fuse
Strip the insulation off of both ends of the 6” red wire to expose 1/4” of bare wire. Pass the wire through the
1/2” diameter shrink tubing. Attach one end to the side lug on the fuse holder and then solder into place.
Pass the smooth edged line cord wire through the 1/2” diameter shrink tubing and attach to the end lug on
the fuse holder, solder into place.
Slide the shrink tubing over the fuse holder covering both lugs. Shrink the tubing for a snug fit. You may use
a hair dryer, heat gun (at lowest setting or you will melt the tubing) or the heat emitting from your soldering
iron (do not touch the tubing or the wires with the iron).
Mount the solder lug to the side panel using a 6-32 x 5/16” screw and 6-32 nut.
Switch
Disconnect the connector for the transformer.
Pass the 6” strip of red wire (leading from the side lug of the fuse holder), the (A) and (B) black transformer
wire, and the ribbed line cord wire through the 3/4” diameter piece of shrink tubing.
Cut the 2” section of 3/16” diameter shrink tubing in half to create two 1” sections. Slide a 3/16” diameter
piece of shrink tubing over the loose end of the red wire. Attach the red wire to lug 1 on the switch and
then solder into place.
Pass the black transformer wire labeled (B) through a 3/16” diameter piece of shrink tubing. Attach the wire
to lug 2 on the switch and then solder into place.
Slide the shrink tubing over lug 1 and lug 2 on the switch. Shrink the tubing into place.
Strip the insulation off of the black transformer wire (A) and the ribbed edged line cord wire to expose 1/2” of
bare wire. Twist the two bare wires together. Pass the wires through the 1/4” diameter piece of shrink tubing.
Attach the wires to lug 3 on the switch and solder into place. Slide the tubing over the lug. Shrink the tubing
into place.
Slide the 3/4” diameter shrink tubing over the switch and shrink into place.
Reconnect the connector for the transformer.
6-32 x 5/16”
Screw
Female Connector
Green Line
Cord Wire
Figure U
1/4” Dia. Shrink Tubing
Ribbed Line Cord Wire
(A) Black
Transformer Wire
(B) Black
Transformer Wire
Smooth Line
Cord Wire
Solder Lug
Switch
3/4” Dia. Shrink Tubing
6” Red Wire
3/16” Dia.
Shrink Tubing
3
2
Switch Pin-out
Shrink Tubing
Side Lug
6-32 Nut
1
1/2” Dia.
Fuse Holder
-14-
RESISTANCE ANALYSIS OF POWER SUPPLY
Static testing of the power supply circuits. Do not plug the power supply into the 120VAC power supply
source until all resistance readings check out. The values given below are approximate.