Elenco Electronics XK-700-SEMI Assembly And Instruction Manual

DIGITAL / ANALOG TRAINER

MODEL XK-700-SEMI

A COMPLETE MINI-LAB FOR BUILDING,TESTING

AND PROTOTYPING ANALOG AND DIGITAL CIRCUITS

Elenco Electronics, Inc.

Assembly & Instruction Manual

INTRODUCTION

The XK-700-SEMI Digital/Analog Trainer is basically divided into four sections: Bredboard, Power Supply, Analog and Digital. The bredboard was sent to you in an earlier kit.The PC board that contains the majority of the circuits has come to you preassembled - HANDLE IT CAREFULL

Y as parts can be broken or moved and could cause the circuit to malfunction. Follow the instructions carefully and perform all tests required. When the assembly of the trainer has been completed, you will do a resistance and voltage analysis. If problems occur, the troubleshooting chart at the end of each section will be helpful. After the Power Supply has been established as functioning correctly, you will analyze the Analog Section ev en though it was preassemb led. That confirms that the circuit is functioning properly when it is powered up. The same procedure will be followed up when checking the Digital Section.

POWER SUPPLY

The XK-700-SEMI has five built-in power supplies which will satisfy most design needs. This includes two variable power supplies giving up to +20 volts and -20 volts at .5 amp. Below 15V, the current available is 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 w ork. All supplies are regulated to within 150mV. This means that you can increase the current draw from no load to .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.

DIGIT AL 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 @ .5 amp (1.25V to 15V @ 1 amp).

• -1.25 to -20VDC @ .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 .2V no load to .5A.

• Line regulation - all DC supplies less than .2V 105 to 135V.

• Hum and ripple - all DC supplies less than .01V RMS.

• Short protection - all DC supplies-inter nal IC ther mal cutoff.

• Fuse 1.25A 250V.

Variable Resistance (undedicated):

• 1kΩ Potentiometer

• 100kΩ Potentiometer

Bredboard - 2 bredboards containing 1,560 tie points.

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 Positive Voltage 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) Output terminals for 1k and 100k undedicated potentiometers.

7) 1kΩ undedicated potentiometer.

8) 100kΩ undedicated potentiometer.

-1-

7 8

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XK-700-SEMI DIGITAL/ANALOG TRAINER PARTS LIST

QTY DESCRIPTION PART #

1 LM317 Integrated Circuit (U1) 330317 1 LM337 Integrated Circuit (U5) 330337 1 LM7805 Integrated Circuit (U3) 337805 1 LM7812 Integrated Circuit (U2) 337812 1 LM7912 Integrated Circuit (U4) 337912 1 Transformer 44K500 1 Fuse 1.25A 530125 1 Switch Illuminated 541204 4 Bracket L 4-40 tap 613008 1 Panel Top 614108 1 Panel Side Left 614506 1 Panel Side Right 614507 1 Panel Back 614508 4 Plastic Plug * 621050 9 Knob 622009 1 Case 623051 1 Strain Relief 624003 1 Spacer Nylon 7/16” 4-40 Tap 624013 1 Connector Receptacle 626020 1 Connector Plug 626021 9 Screw 4-40 x 1/4” Slotted Machine 641430 1

Screw 4-40 x 1/4” Phillips Flat Head

641431 6 Screw 6-32 x 5/16” Slotted Machine 641641 2 Screw 8-32 x 3/8” Phillips Machine 641840 4 Screw #4 x 1/4” Phillips AB 642430 4

Screw 4-40 x 1/4” Phillips Thrd Ct (23)

642432 4 Screw #6 x 1/2” Phillips AB 642662 4

Screw #6 x 3/8” Phillips Thread Cutting (25)

643652

* Used in Trainer Case Conversion Section on page 35.

QTY DESCRIPTION PART #

7 Nut 7mm 644101 2 Nut 9mm 644102 6 Nut 6-32 644601 2 Nut 8-32 644800 7 Washer 8mm x 14mm 645101 2 Washer 9mm x 15mm 645103 4 Washer #6 Black 645400 4 Washer Fiber 645404 2 Lockwasher #8 External 646828 1 Lug Solder #8 661002 1 Fuse Holder 663000 2 Terminal Male Crimp 666010 2 Terminal Female Crimp 666011 1 Manual 753045 5 Insulator Mica 780002 5 Insulator Washer 780101 1 Silicon Grease 790004 6” Wire #20 Red Stranded 813210 1 Line Cord 862105 2” Shrink Tubing 3/16” 890120 1” Shrink Tubing 1/4” 890701 2” Shrink Tubing 1/2” 891101 2” Shrink Tubing 3/4” 899110 1 PC Board Assembly 920550HK 1 9426 Bredboard 99426 1 9830 Bredboard 99830 1 Solder Tube 9ST4

Screw Identification

Phillips AB Screw 4-40 Thread Cutting Screw

#6 Thread Cutting Screw

Phillips

Slotted Machine

Screw

Flat Head Screw

Phillips

Phillips Machine Screw

-3-

PARTS VERIFICA TION

Before beginning the assembly process, first familiarize yourself with the components and this instruction book. Ver ify that all par ts are present. This is done best by checking off each item in the parts list.

RESISTORS CAPACITORS

Trim Pot

Pot

Discap Mylar

Electrolytic (radial)

(Lytic)

SEMICONDUCTORS

INTEGRATED CIRCUIT

Diode

Transistor

IDENTIFYING CAPACITOR VALUES

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.

Second Digit

First Digit

Multiplier Tolerance

The above value is 10 x 1,000 = 10,000pF or .01µF The letter K indicates a tolerance of +

10%

The letter J indicates a tolerance of +5%

For the No. 01234589 Multiply By 1 10 100 1k 10k 100k .01 0.1

Multiplier

Note: The letter “R” may be used at times to signify a decimal point; as in 3R3 = 3.3

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 Multiplier Black 1 Brown 10 Red 100 Orange 1,000 Yellow 10,000 Green 100,000 Blue 1,000,000 Silver 0.01 Gold 0.1

Resistance

Tolerance

Color Tolerance Silver +10% Gold +5% Brown +

1% Red +2% Orange +

3% Green +

.5% Blue +.25% Violet +

.1%

Bands

1 2

Multiplier

Tolerance

-4-

CONSTRUCTION

Introduction

Assembly of your XK-700-SEMI Digital/Analog Trainer Kit will prove to be an exciting project and give you much satisfaction and personal achievement. If you have e xperience in soldering and wiring techniques, then you should ha v e no problem with the assemb ly of this kit. Care must be given to identifying the proper components and in good soldering habits. Above all, take your time and follow these easy step-bystep instructions. Remember, “An ounce of prevention is worth a pound of cure”. Avoid making mistakes and no problems will occur.

CAUTION: WEAR SAFETY GLASSES WHEN ASSEMBLING THIS KIT. Assemble Components

In all of the following assembly steps , the components must be installed on the top side of the PC board unless otherwise indic ated. The top legend shows where each component goes. The leads pass through the corresponding holes and the board is tur ned to solder the component leads on the foil side. Solder immediately unless the pad is adjacent to another hole which will interfere with the placement of the other component. Cut excessive leads with a diagonal cutter. Then, place a check mark in the box provided next to each step to indicate that the step is completed. Be sure to save the extra leads for use as jumper wires if needed.

Soldering

The most important factor in assembling your XK-700-SEMI is good soldering techniques. Using the proper solder ing 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. Many areas on the PC board are close together and care must be given not to form solder shorts. Size and care of the tip will eliminate problems.

For a good soldering job, the areas being soldered must be heated sufficiently so that the solder flows freely. Apply the solder simultaneously to the component lead and the component pad on the PC board so that good solder flow will occur. Be sure that the lead extends through the solder smoothly indicating a good solder joint. Use only rosin core solder of 60/40 alloy. DO NOT USE ACID CORE SOLDER! Do not blob the solder over the lead because this can result in a cold solder joint.

1. Solder all components from the copper foil side only. Push the soldering iron tip against both the lead and the circuit board foil.

Component Lead

Soldering Iron

Circuit Board

Foil

2. First 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

Example 1

Poor solder connections occur when the lead is not heated sufficiently. The solder will not flow onto the lead as shown.T o correct. reheat the connection and, if necessary , apply a small amount of additional solder to obtain a good connection.

Solder does not flow onto the lead. A hard rosin bead surrounds and insulates the connection.

Poor solder connection

Mount Part

Soldering iron positioned incorrectly.

Example 2

A solder bridge occurs 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 iron across the solder bridge as shown.

4. Here is what a good solder connection looks like. Cut off excess leads.

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

Bend Leads to Hold Part Solder and Cut Off Leads

Foil Side

Rx - 100Ω 5% 1/4W Resistor

(brown-black-brown-gold)

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” machine screw and a fiber washer.

-5-

INSTALL COMPONENTS TO PC BOARD

Install the four L-brackets in the positions shown in Figure A. Mount them into position as shown in Figure B.

Figure A Figure B

Place the top panel onto the PC board and align the components with the holes in the top panel.

4-40 x 1/4”

Machine

Screw

Top Legend

Side of

PC Board

Fiber

Washer

Longer Side

-6-

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.

Mount the back panel using four 4-40 x 1/4” thread cutting screws (see Figure C).

Mount the PC board with four 4-40 x 1/4” machine screws (see Figure D). Do not tighten the screws.

4-40 x 1/4” Thread

Cutting Screws

4-40 x 1/4” Thread

Cutting Screws

Back Panel

Figure C

Right Side

Left Side

Figure D

4-40 x 1/4”

Machine Screws

4-40 x 1/4”

Machine Screws

Top Legend Side

of PC Board

Note: From the f oil side of the PC board, inspect the edges to be sure that there are no component leads shorting against the side panels.

Right Side

Left Side

-7-

MOUNT COMPONENTS TO THE SIDE P ANELS

Mount U1, U3 and U5 to the left side panel as shown in Figure G. Insert the pins of each IC into the holes of the PC board. Then, with the hardware shown in Figure F, attach each IC to the side panel. Solder the pins of the ICs to the PC board.

U3 - LM7805 U1 - LM317 U5 - LM337

Figure G

Mount the solder lug to the panel, as shown in Figure G, using a 6-32 x 5/16” screw and 6-32 nut.

Solder Lug

Mica

Side Panel

Insulator Washer

6-32 x 5/16”

Machine Screw

* Take a small amount of silicone grease from the packet and apply it with a toothpick onto the back of the ICs.

Figure F

6-23 Nut

* Silicone Grease

Mica

IMPORTANT

Place the top panel on top of the unit. Push the PC board up until the components come through the top panel and tighten the screws.

Adjust the PC board height with a 4-40 x 1/4” machine screw.

Figure E

7805

LM317

LM337

Solder Lug

6-32 Nut 6-32 x 5/16”

Screw

Left Side

-8-

WIRE THE TRANSFORMER TO THE PC BOARD

Cut the blue, red, white and yellow wires on the transformer so they are 3” long and strip the insulation off of the ends to expose 1/4”of bare wire. Solder the wires to the PC board starting with the top yellow wire as shown in Figure I.

Yellow (F) wire to point F on the PC board Blue (A) wire to point A on the PC board Red (C) wire to point C on the PC board White (E) wire to point E on the PC board Red (D) wire to point D on the PC board Blue (B) wire to point B on the PC board Yellow (G) wire to point G on the PC board

Yellow (F) Blue (A) Red (C) White (E) Red (D) Blue (B)

Yellow (G)

Figure I

3”

Mount U2 and U4 to the right side panel as shown in Figure H. Insert the pins of each IC into the holes in the PC board. Then, with the hardware shown in Figure FA, attach each IC to the side panel. Solder the pins of the ICs to the PC board.

U4 - LM7912 U2 - LM7812

Mount the transformer with the black wires as shown in Figure H. Use the two 8-32 x 3/8” machine screws, #8 lockwashers, and 8-32 nuts.

Transformer mounted

#8-32 x 3/8” Machine Screws

6-23 Nut

* Silicone Grease

Mica

Side Panel

Insulator Washer

6-32 x 5/16”

Machine Screw

* Take a small amount of silicone grease from the packet and apply it with a toothpick onto the back of the ICs.

Figure FA

Mica

Yellow (G)

Blue (B)

Blue (A)

Red (D) White (E) Yellow (F)

Red (C)

Right Side

7812

7912

Figure H

Black Wires

8-32 Nut

#8 Lockwasher

8-32 Nut

Transformer

Note: Make sure that the transformer does not touch U4.

-9-

HOW TO INSTALL CONNECTORS ONTO TRANSFORMER WIRES

A connector will be placed in the primary wires of the transformer. This will allow you to remove the top panel from the trainer. Follow the procedures below.

1. Cut a six inch length off of each black primary wire.

2. Strip the insulation off of each end of the six inch wires to expose 1/4” of bare wire.

3. Place one wire onto the female pin and crimp the outer crimp tabs with pliers over the insulation as shown

in Figure 1A.

4. Crimp the inner tabs with pliers onto the bare wire as shown in Figure 1B and then solder the wire to the pin.

5. Connect the other female pin to the other wire using the same procedures above.

Locking Tab

Female Pin

Solder

Outer

Crimp Tab

Inner Crimp Tab

Female Housing

Figure 1

Figure 2

6. 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.

TRANSFORMER WIRES

1. Strip the insulation off of each of the black primary wires to expose 1/4” of bare wire.

2. 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 and then solder the wire to the pin as shown in Figure 3B.

4. Connect the other male pin to the other primary wire using the same procedures above.

5. 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 wa y.

7. To detach the connector, push down on the end of the lock arm and pull the two apart.

Figure 3

Figure 4

Locking Tab

Male Pin

Solder

Outer

Crimp Tab

Inner Crimp Tab

Male Housing

Lock Arm

Figure 5

-10-

MOUNT COMPONENTS TO PANEL

Push the illuminated switch into the hole in the top panel with the lugs as shown in Figure J. Install the fuse holder with the side lug in the position shown in Figure J. Fasten the fuse holder in place with

the nut as shown in Figure K. Unscrew the cap and inser t the fuse into the holder.

Back Side - Lower

Right Corner

Figure J

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 L).

Put the two bredboards together as shown in Figure Ka. When mounting the bredboard, use the holes shown in Figure Kb. Mount the plastic spacer with a 4-40 x

1/4” flat head screw as shown in Figure L. Next, mount the bredboards with two #4 x 1/4” AB black screws from the back side of the top panel as shown in Figure L. The negative (blue) stripe should be on top and the numbers reading from left to right should start with number 1 (see Figure M). CAUTION: Do not remove the paper backing from the back of the bredboards. Do not over-tighten the black screws.

9426

9830

9426

Use these

holes

Use these

holes

Figure Ka

Figure Kb

Side

Lug

Fuse Holder

Illuminated Switch

Nut

Top Panel

Plastic Washer

Fuse Holder

Figure K

Spacer

4-40 x 1/4”

Flat Head

Screw

Top Panel

Bredboard

#4 x 1/4” AB Screws

Figure L

REGULATED

POWER SUPPLY

GND

-12

+12

OFFON

30VAC

15VAC

Figure M

15VAC

-11-

+ 28 hidden pages

Elenco Electronics XK-700-SEMI Assembly And Instruction Manual

Specifications and Main Features

Frequently Asked Questions

User Manual