STEP 1 - Tutorial



Building the Hardware

The most important skills one can have when building a board are the ability to attend to detail and to solder. I can’t help you with the first, but I can provide some soldering tips.

Use an iron of about 30 watts with the smallest tip you can find.

Coat the tip of the iron with solder as soon after you plug it in as possible.

Wet a sponge and occasionally wipe the tip on it to keep it shining silver.

To solder a component on the board:

1. Insert the component and push it in so it is flat on the board.

2. Splay the leads so the component won’t fall out.

3. Place the board component side down on the table. For long wire components, cut the wire to about 1/8”. Don’t worry about cutting leads on such things as integrated circuits. Their wires are already the correct length.

4. Place the tip of the soldering iron and the solder on the pad to be soldered so that both are touching the component’s wire.

5. Let the solder flow onto the pad and the wire.

6. As soon as you see the solder coat the whole pad and get on the wire, lift the soldering iron and solder up from the pad at about the same time, with the solder slightly leading the iron.

7. Check your work. You should have formed a cone from the pad up on to the wire. It should be shiny. There should not be a space between the solder and the wire. The connection should not bridge to an adjacent pad. Use a solder sucker or a solder wick to remove any bridges.

HOW TO SOLDER, BY

At

Soldering is a delicate manual skill which only comes with practice. Remember that your ability to solder effectively will determine directly how well the prototype or product functions during its lifespan. Poor soldering can be an expensive business - causing product failure and downtime, engineer's maintenance time and customer dissatisfaction. At hobbyist level, bad soldering technique can be a cause of major disappointment which damages your confidence. It needn't be like that: soldering is really easy to learn, and like learning to ride a bike, once mastered is never forgotten!

These photos illustrate the basic steps in making a perfect solder joint on a p.c.b. If you're a beginner, our advice is that it's best to practice your soldering technique using some clean, new parts with perhaps some new stripboard (protoboard). Be sure to avoid using old, dirty parts; these can be difficult if not impossible to solder.

EPE published a comprehensive five-part series called "Build Your Own Projects" which shows you how to construct electronic prototypes, and how to make printed circuit boards, from scratch. It appeared in EPE November 1996 - March 1997. Check back issues at: htp://epemag.wimborne.co.uk/backiss.htm for more details of availability and prices. Enjoy! Alan Winstanley.

| |Clean the iron "bit" (tip) |[pic] | |

| |using a damp sponge. Iron | | |

| |featured is an Ungar Concept | | |

| |2100 Soldering Station. | | |

|[pic] |(Left) A useful product is |[pic] | |

| |Multicore's Tip Tinner Cleaner | | |

| |(TTC) - a 15 gramme tin of | | |

| |special paste which cleans and | | |

| |"tins" the iron, in one go. | | |

| |(Right) Insert components and | | |

| |splay the leads so that the | | |

| |part is held in place. | | |

|[pic] |(Left) It's usually best to |[pic] | |

| |snip the wires to length prior | | |

| |to soldering. This helps | | |

| |prevent transmitting mechanical| | |

| |shocks to the copper foil. | | |

| |(Right) Apply a clean iron tip | | |

| |to the copper and the lead, in | | |

| |order to heat both items at the| | |

| |same time. | | |

|[pic] |(Left) Continue heating and |[pic] | |

| |apply a few millimetres of | | |

| |solder. Remove the iron and | | |

| |allow the solder joint to cool | | |

| |naturally. | | |

| |(Right) It only takes a second | | |

| |or two, to make the perfect | | |

| |joint, which should be nice and| | |

| |shiny. Check the Guide for | | |

| |troubleshooting help. | | |

|[pic] |(Left) An example of a "dry" |[pic] | |

| |joint - the solder failed to | | |

| |flow, and instead beaded to | | |

| |form globules around the wire. | | |

| |(Right) "Solder Wick" is a | | |

| |cheap and very effective way of| | |

| |desoldering a joint. Take care | | |

| |not to overheat the board. | | |

| |Alternatively, use a | | |

| |desoldering pump. | | |

Small-print: these photos are Copyright © Alan Winstanley 1997. However, you are free to download them for personal or educational use: help yourself. If you wish to use them for any commercial reasons, all I ask is that you seek my prior approval first at alan@epemag.demon.co.uk.

For the photographer: the photographs were taken by the author using a Minolta X-700 SLR with 50mm

Minolta MC manual-focus macro lens at f11-16, coupled to a Minolta Auto 80PX macro ring flash gun. Film was Kodak Gold 200. The prints were scanned using an HP Scanjet 4C flatbed scanner, and enhanced using JASC Paintshop Pro 4.1 before being uploaded to the EPE web site.

V1.1 Last updated 3rd April 1997

The following is a color code table from the University of Pennsylvania. A resistor is a device that resists the flow of charge. The unit of resistance is the ohm, pronounced om with a long o. As you can see, resistors are read by the use of two significant digit colors, one multiplier and one tolerance color. Think of the multiplier as the number of 0's stuck on the end. For example, just put 3 0's after the 27 below. Note that the K stands for kilo or thousand. You will also see Meg in the instructions. It means million. So brown, violet, green means put down a 4 then a 7 then 5 0's, or 4700000 which means 4,700,000 or 4.7Meg ohms. To keep things uniform, it would probably be a good idea to install the resistors with the colors from left to right or top to bottom in the order of colors shown in the instructions.

The board also uses variable resistors for offset, bass, treble and volume. They usually have their values printed on them, but can also have a code number that works like the resistor code. For example, 103 means put a 1 down, then a 0, then 3 more 0's, which gives 10000 ohms or 10K ohms.

Capacitors are devices which have metal plates separated by an insulator. They are used to temporarily store an electrical charge. The unit of capacitance is the Farad, but it's so large that the practice is to use the microfarad, or millionths of a Farad. Capacitors are labeled many different ways. You will probably find three methods on the he board. An electrolytic capacitor is usually labeled in plain English, such as 330MF or 10mf. Electrolytics are also polarized. They have a negative and positive end and must be installed correctly polarized.

The other capacitors might also be labeled similarly, such as .1MF. It's about as common however, for them to be labeled with a number code. The .1MF for example, would be 104. This works like the resistors in that you have a 1 as the first significant figure, the 0 as the second significant figure and you put 4 0's on the end. You end up with 100000 picofarads, which is 10E-12 Farads which is one billionth of a Farad (En means 10 raised to the n). What you end up with is 10E5 * 10E-12 = 10E-7 which is the same as .1MF.

A diode is a device that allows a charge to flow in only one direction. Charge flows from negative to positive. It's a little like lighting. Lighting travels from a cloud where there is a greater negative charge to the earth, except near the end of a storm or in the winter when the earth has accumulated more electrons and is thus more negative. It then travels up rather than down. The stripe on a diode designates the cathode or negative end. Thus, a charge can flow through the diode from the striped end. It can't go the other way.

The hardware is constructed on a printed circuit board. Its layout is shown below. Install the components on the board according to the steps on the following pages.

A parts list is at the end of this document.

STEP 1

Install resistors R1, R2, R3 and R4 in the positions shown, splay their leads on the back of the board to keep them from falling out, turn the board over, cut the leads close to the board then solder them.

R3, 15K R1, 3.9K

brown, green, orange orange, white, red

R4, 15K R2, 4.7Meg

brown, green, orange yellow, violet, green

STEP 2

Install R5, R6, R7 and R8 the same way you installed the resistors in step 1.

R6, 470 R7, 10K

yellow, violet, brown brown, black, orange

R5, 470 R8, 10K

yellow, violet, brown brown, black, orange

STEP 3

Install R9, R10 and R11 the same way you installed the resistors

in step 1.

R11, 150K R9, 10K

brown, green, yellow brown, black, orange

R10, 3.3K

orange, orange, red

STEP 4

Install D1 and D2 the same way you installed the resistor, except make sure the stripes are in the correct places.

D2 D1

1N4148 1N4148

STEP 5

Install the .22MF capacitors C1 and C3 in the positions shown. Splay their leads on the back of the board to keep them from falling out, turn the board over, cut the leads close to the board then solder them to the board.

C3 C1

.22mf .22mf

STEP 6

Install the two .1MF capacitors C10 and C11 as shown below.

C11 C10

.1MF .1MF

STEP 7

Install the two .1MF capacitors, C12 and C13 in a like manner.

C13 C12

.1MF .1MF

STEP 8

Now install the four .1MF capacitors C9, C14, C15 and C16 in a like manner.

C14 C15 C16 C9

.1MF .1MF .1MF .1MF

STEP 9

Install the .01MF capacitors C4, C5, C6 and C7 as shown below.

C6 C7 C4 C5

.01MF .01MF .01MF .01MF

STEP 10

Install C2, a 10MF electrolytic capacitor. Make sure the negative end is to the left and the positive to the right.

C2

10MF

STEP 11

Install C3, a 330MF electrolytic capacitor. Make sure the positive end is to the left and the negative end to the right.

C8

330 MF

STEP 12

Install VR1, the 10K variable resistor offset trimmer, in the position shown below.

VR1

10K

STEP 13

Install the three variable resistors VR2, VR3 and VR4 as shown below.

VR2 VR3 VR4

100K 100K 10K

STEP 14

Install ARRAY 2 as shown below. Make sure pin 1 is to the right as shown. It might be shown with a stripe, a number or a dot on the end.

ARRAY 2

10K, 7 RESISTORS, ONE COMMON

PIN 1

STEP 15

Please note that the device numbers for the ICs are printed on the board. While they are shown as 74LS devices, others may be used that have different prefixes. Just look for the generic part of the number. For example, a 74LS02's generic would be 74xx02, where xx could be anything, such as LS, AH, etc.

Install IC1, IC2, and IC5 in the positions shown below. You will probably need to straighten the pins by rolling the ICs over on their edges. Be sure to use the correct IC and to get the notches to the left! Not doing so can destroy not only the board, but your computer as well! Pin 1 will be the bottom left pin. Splay two diagonal pins slightly on each to keep them from falling out. Now tack the diagonals (solder them with just a touch of solder). While pushing in on an IC from the top of the board, heat each of the pins you just tacked. The idea is to make sure the IC is snug and flat on the board. Now solder all leads normally.

IC2 IC1 IC5

74LS02 TL074 DAC0832

STEP 16

Install IC4 using the same methods you did above.

IC4

ADC0809

STEP 17

Now install IC7 and IC8.

IC7 IC8

74LS244 74LS08

STEP 18

Now install the five ICs, IC9, IC10, IC11, IC12 and IC13 near the bottom edge of the board.

IC9 IC10 IC11 IC12 IC13

74LS393 74LS138 74LS688 74LS245 LM380N-8

STEP 19

Install the selector switch and jumper 1, a 2 pin header with .1" spacing between the pins. It might be a little snug. If so, press it in using a flat metal surface of some sort, such as the flat of a screwdriver blade. Be sure to install the jumper plug over the jumper pins. Install the selector DIP switch. The printing should be oriented the same as the ICs.

Jumper 1

Switch 1 (readable same as ICs)

STEP 20

Install Jack 1 for the microphone and Jack 2 for the speaker.

J2 Speaker Output J1 Mike Input

STEP 21

Install IC6, a DAC0832, the second digital to analog converter.

IC6

DACO832

STEP 22

Install IC3, header 1 and header 2. IC3 is the Programmable Peripheral Interface. The headers have .1" spacing between pins and between rows.

IC3 Header 2 Header 1

STEP 23

The final step is to install ARRAY1, header 3 and header 4. This completes construction of the hardware.

HEADER 4 HEADER 3 ARRAY 1, PIN 1

Parts Needed For Digital Experiments

(These will get you started. I priced them at $18.65, mostly from Jameco .)

|Capacitors |

|C9, C10, C11, C12, C13, C14, C15, C16 |.1MF .2", or 5mm spacing, anything above 12 volts OK, ceramic OK |

 

|Resistor Arrays or Networks |

|ARRAY1 |9 resistor, 10 pin 10K SIP with one end of each resistor commoned to pin 1 |

|ARRAY2 |7 resistor, 8 pin 10K SIP with one end of each resistor commoned to pin 1 |

 

|DIP Switch |

|SW1 |Three Position DIP Switch |

|Headers -- All have two rows .1" apart with pins .1" apart |

|HEADER 1 |2 X 8 pin header |

|HEADER 2 |2 X 5 pin header |

|HEADER 3 and 4 |2 X 13 pin headers |

|Integrated Circuits -- 74, 74HCT, 74AHC, etc. prefixes may be substituted for 74LS |

|IC2 |74LS02 quad NOR gate |

|IC3 |8C255 Programmable Peripheral Interface |

|IC7 |74LS244 octal buffer |

|IC8 |74LS08 quad AND gate |

|IC9 |74LS393 counter |

|IC10 |74LS138 1 of 8 decoder |

|IC11 |74LS688 digital comparator |

|IC12 |74LS245 octal transceiver |

Additional Parts Needed For Remaining Experiments

(I priced these parts at about $24.00, mostly from Jameco .)

|Variable Resistors |

|VR1 |10K OFFSET TRIMMER (25 turn) equal to Bourns type 3296X |

|VR2 |100K BASS TRIMMER equal to Bourns type 3386C |

|VR3 |100K TREBLE TRIMMER equal to Bourns type 3386C |

|VR4 |10K VOLUME TRIMMER equal to Bourns type 3386C |

|Capacitors |

|C1, C3 |.22MF .2" or 5mm spacing film similar to Panasonic |

| |ECQ-V1H224JL |

|C2 |10MF 25v axial electrolytic similar to Panasonic |

| |ECE-B1EU100S |

|C4, C5, C6, C7 |.01MF .2" or 5mm spacing film similar to Panasonic |

| |ECQ-V1H103JL |

|C8 |330MF 6.3v axial electrolytic similar to Panasonic |

| |ECE-B0JU331 |

|Jumper |

|JP1 |.1" Header Type Jumper |

|Diodes |

|D1, D2 |1N4148 switching diode |

|IN/OUT CONNECTORS |

|J1, J2 |Switchraft 1/8" phone jack -- Mouser Electronics # 16PJ528 |

|Resistors -- All Are 1/8 Watt |

|R1 |3.9K |

|R2 |4.7M |

|R3, R4 |15K |

|R5,R6 |470 |

|R7,R8,R9 |10K |

|R10 |3.3K |

|R11 |150K |

 

|Integrated Circuits |

|IC1 |TL074 or LF347A quad op amp |

|IC4 |ADC0809 8 input, 8-bit AD converter |

|IC5, IC6 |DAC0832 8-bit DA converter |

|IC13 |LM380N-8 power amp (8 pin DIP version) |

 

PARTS SOURCES

A

AAA The Bottom Line Surplus

Alltronics

All Electronics Corp

Allied Electronics

Avnet Electronics

Alpha & Omega Electronics Surplus Electronics

ATMEL

B

Byers Chassis Kits

C

Chip directory

Circuit Specialists

Capital Electronics

Complete Computer Solutions, Inc

Computer & Computer Engineering Resources, by Category, Ramey Corporation

Computer Liquidations, LTD

D

Digi Key

E

EIO Electronics Surplus

Electrical Engineering Vendors

electroBASE

listing of distributors, representatives, services, and component manufacturers

Electronet

Electronic Parts Data Base

Electronic Component Distributors

Electronic Surplus Electronics Components

Electronics Bookmark -- Some Resources

Electronics PARTS SUPPLIERS List

Electronics Surplus -- DW Elect

Electronix Express

Excess, Surplus Electronics Directory

F

FaradNet Home Page

Futurlec Electronic Components

G

Gray's Brief Semiconductor URL Page

H

Harry Krantz Company

HSC Electronic Supply

I

J

Jameco Electronics

JDR Micro Electronics

K

Kelvin Electronics

MECI Electronics

M.C. Howard Electronics

Maxim

Mitel Semiconductor

MX-COM

Miscellaneous links

Mondo-tronics' Robot Store

Mouser Electronics

Mushroom Components

N

National Semiconuctor

Nerd World Electronic Components

Newark

New, used, and surplus computer equipment

Norm's Industrial Electronics Component Manufacturers

Now! Components Ltd

Provides an eCommerce service for buyers and sellers of electronic components.

Nuts & Volts Magazine

O

Oatley Electronics - Links To Other Sites

Q

Quality Kits On-Line Catalog

"We offer a wide selection of electronic kits for the beginner or more advanced projects for the electronics expert. Quality Electronic kits from Maplin Electronics, Velleman - kit and DIY Electronics."

R

R & D Electronics

RadioShack

Ramsey Electronics

Rich's Surplus Electronics Warehouse

S

Semicon Internet Information System

Surplus Al's

Surplus - clearance sales - liquidations

Surplus Direct

Surplus Electronic Parts G-G Enterprises

Surplus Electronic Parts -- Telepath

Surplus Electronic Source List

Surplus Electronics Market

Surplus Traders - 750 Page Computer and Surplus

Switchcraft

T

Tandy Corporation Home Page

Tanner Electronics

Tech America

TI Logic Home Page

COMPILER, ASSEMBLER AND DEBUGGER

MIX Software

1132 Commerce Drive

Richardson TX 75081

(800) 333-0330 (orders only)

(214) 783-6001 (other)

Printed Circuit Boards

Lower quantities of bare, silk-screened, solder-masked boards with gold-plated

edge-board connectors can be purchased from me for $20 each, postage paid. I'll

even sell you a complete board with the expanded capabilities for $75 if that's

what you want, although I'd rather hear of people (especially youth)making their

own. A kit consisting of a board and parts is $50. Texas residents, please don't worry about the tax -- I'll pay it -- how many times have you seen that?

Joe Reeder

1455 N. Perry #1205

Carrollton TX 75006

You can save if you need greater quantities of bare boards:

|QUANTITY |PRICE EACH |

|1 to 4 |$20.00 |

|5 to 14 |$18.90 |

|15 to 24 |$18.65 |

|25 to 49 |$18.45 |

|50 to 99 |$18.35 |

|100 to 249 |$18.30 |

|250 to 499 |$17.50 |

|500 to 999 |$17.15 |

|1000 Up |$16.75 |

One way to pay is through PayPal on the site. As a bonus, they offer $5 just to sign up. That means a single bare board only costs you $15!

Shipping:

• within 24 hours for 20 or fewer boards if paid with PayPal, money order or cashier's check

• 2 to 3 weeks for quantities between 20 and 100 if paid with PayPal, money order or cashier's check

• 3 to 4 weeks for kits if paid with PayPal, money order or cashier's check

• 4 to 6 weeks for quantities greater than 100, for assembled boards or if payment is made with a check

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