Elenco Digital Mulitmeter Kit User Manual

DIGITAL MULTIMETER KIT

MODEL M-1007K

Assembly and Instruction Manual

Elenco®Electronics, Inc.

Copyright © 2008 by Elenco®Electronics, Inc. All rights reserved. 753096

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 meter 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.

RESISTORS (Parts mounted on card.)

Qty. Symbol Value Color Code Part #

r 1 R10 .99Ω .5% 1/4W black-white-white-silver-green 109950
r 1R8 9Ω .25% 1/4W white-black-black-silver-blue 119050
r 1 R20 100Ω .25% 1/4W brown-black-black-black-blue 131060
r 1 R21 900Ω .25% 1/4W white-black-black-black-blue 139060
r 1R5 1kΩ 5% 1/4W brown-black-red-gold 141000
r 1R6 3kΩ 1% 1/4W orange-black-black-brown-brown 143030
r 1 R22 9kΩ .25% 1/4W white-black-black-brown-blue 149060
r 1 R7 30kΩ 1% 1/4W orange-black-black-red-brown 153030
r 1 R23 90kΩ .25% 1/4W white-black-black-red-blue 159060
r 2 R4, R30 100kΩ 5% 1/4W brown-black-yellow-gold 161000
r 3 R24, R25, R35 117kΩ .5% 1/4W brown-brown-violet-orange-green 161160
r 1 R1 150kΩ 5% 1/4W brown-green-yellow-gold 161500
r 6 R12-15, R18, R19 220kΩ 5% 1/4W red-red-yellow-gold 162200
r 2 R26, R27 274kΩ .5% 1/4W red-violet-yellow-orange-green 162750
r 1 R2 470kΩ 5% 1/4W yellow-violet-yellow-gold 164700
r 1R3 1MΩ 5% 1/4W brown-black-green-gold 171000

Resistors with 0.25% tolerance may be included instead of 0.5%.

These parts are not mounted on card:

r 1R9 0.01Ω Shunt Wire 100165
r 1 VR1 220Ω (221) Potentiometer 191310
r 1 R32 2kΩ PTC Resistor 142069

CAPACITORS

Qty. Symbol Value Description Part #

r 1 C1 100pF (101) Disc 221017
r 4 C2, C3, C4, C5 .1μF (104) Mylar (small) 251017S
r 1C7 .1μF (104 or 0.1) 5% 63VMylar (large) 251017L

SEMICONDUCTORS

Qty. Symbol Value Description Part #

r 1 D3 1N4007 Diode (mounted on resistor card) 314007
r 1 Q1 9013 Transistor 329013

MISCELLANEOUS

-1-

Qty. Description Part #

r 1 LCD 351117
r 1 Zebra 6.8 x 40mm 500007
r 1 PC Board IC Installed 516105
r 1 Fuse 0.5A, 250V 533004
r 1 Battery 9V 590009
r 1 Battery Snap 590098
r 1 Selector Knob 622107
r 1 Case Top (Black) 623090
r 1 Case Bottom (Black) 623095
r 1 Zebra Clip 629018
r 3 Screw 2mm x 6mm 643439
r 2 Screw 2mm x 10mm 643447

Qty. Description Part #

r 2 Fuse Holder Clips 663100
r 1 Transistor Socket 664007
r 3 Input Socket 664105
r 2 Ball Bearing 666400
r 6 Slide Contact 680013
r 2 Spring 1/4” (Selector Knob) 680014
r 1 Spring 1/2” 680015
r 1 Label Front 724015
r 1 Label Shield 780010
r 1 Grease 790004
r 1 Lead-Free Solder 9LF99
r 1 Test Lead Set TL1007

NOTE: The 7106 IC1 is already installed on the PC board. This type of installation is called C.O.B. (chip on board).

The following parts are not used / listed: R11, R16, R17, R28, R29, R31, R34, C6, D1, and D2.

-2-

IDENTIFYING RESISTOR VALUES

Use the following information as a guide in properly identifying the value of resistors.

5 Bands

1 2

Multiplier

Tolerance

Resistors

PARTS IDENTIFICATION

PC Board with IC

Potentiometer

Ball Bearing

Selector Knob

Battery Snap

Fuse

Clip

Slide

Contact

Transistor

Socket

Fuse

Input Socket

3

4 Bands

1

2

Multiplier

Tolerance

Diode

Shunt Wire

LCD Assembly

Zebra Clip/Zebra/LCD

Capacitors

Discap

Mylar

C7

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. The maximum operating voltage may also be printed on the capacitor.

Second Digit

First Digit

Multiplier

Tolerance*

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

10μF 16V

103K

100V

The letter M indicates a tolerance of +20%
The letter K indicates a tolerance of +10%
The letter J indicates a tolerance of +

5%

Maximum Working Voltage

The value is 10 x 1,000 =
10,000pF or .01μF 100V

*

Zebra

Clip

Zebra

LCD

Electrolytic capacitors have a positive and a
negative electrode. The negative lead is
indicated on the packaging by a stripe with
minus signs and possibly arrowheads.

Warning:

If the capacitor is
connected with incorrect
polarity, it may heat up
and either leak, or cause
the capacitor to explode.

Polarity
Marking

Springs

-3-

CONSTRUCTION

Solder

Soldering Iron

Foil

Solder

Soldering Iron

Foil

Component Lead

Soldering Iron

Circuit Board

Foil

Rosin

Soldering iron positioned
incorrectly.

Solder

Gap

Component Lead

Solder

Soldering Iron

Drag

Foil

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.

1. Insufficient heat - the solder will

not flow onto the lead as shown.

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.

2. Insufficient solder - let the

solder flow over the connection
until it is covered.
Use just enough solder to cover
the connection.

3. Excessive solder - could make

connections that you did not
intend to between adjacent foil
areas or 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 iron across the solder
bridge as shown.

What Good Soldering Looks Like

A good solder connection should be bright, shiny, smooth, and uniformly
flowed over all surfaces.

Types of Poor Soldering Connections

Introduction

The most important factor in assembling your M-1007K Digital Multimeter 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 rosin-flux core.

Lead-free solder is different from lead solder: It has a higher melting point
(about 440

O

F, compared to about 360OF for lead solder), so you need
higher temperature for the solder to flow properly. Recommended tip
temperature is 700OF-800OF; 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 largest tip possible for best heat transfer.

• 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 (Elenco®#TTC1).

• DO NOT use a sponge, this worsens tip life because the temperature
shocks accelerate corroding of the tip. If you insist on using a sponge,
use distilled water (tap water has impurities that accelerate corroding).

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.

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.
DO NOT USE ACID CORE SOLDER!

'

-4-

ASSEMBLY INSTRUCTIONS

Identify and install the following parts as shown. After soldering each part, mark a check þ in the box provided.
Be sure that solder has not bridged to an adjacent pad.

Figure BFigure A

Stand resistor on end as
shown. Solder and cut
off the excess leads.

R15 - 220kΩ 5% 1/4W Resistor

(red-red-yellow-gold)

(see Figure A)

C2 - .1μF (104) Mylar Cap.

(small yellow)

C1 - 100pF (101) Discap

R1 - 150kΩ 5% 1/4W Resistor

(brown-green-yellow-gold)

(see Figure A)

C4 - .1μF (104) Mylar Capacitor

(small yellow)

R3 - 1MΩ 5% 1/4W Resistor

(brown-black-green-gold)

(see Figure A)

C3 - .1μF (104) Mylar Capacitor

(small yellow)

C5 - .1μF (104) Mylar Capacitor

(small yellow)

R14 - 220kΩ 5% 1/4W Resistor

(red-red-yellow-gold)

(see Figure A)

R13 - 220kΩ 5% 1/4W Resistor

(red-red-yellow-gold)

(see Figure A)

Mount the potentiometer to the PC board as shown.

R5 - 1kΩ 5% 1/4W Resistor

(brown-black-red-gold)

(see Figure A)

C7 - .1μF 63V Mylar Cap.

(104 or 0.1)

R30 - 100kΩ 5% 1/4W Resistor

(brown-black-yellow-gold)

(see Figure A)

VR1 - 220Ω (221) Potentiometer

(see Figure B)

R6 - 3kΩ 1% 1/4W Resistor

(orange-black-black-brown-brown)

(see Figure A)

R7 - 30kΩ 1% 1/4W Resistor

(orange-black-black-red-brown)

(see Figure A)

R4 - 100kΩ 5% 1/4W Resistor

(brown-black-yellow-gold)

(see Figure A)

R2 - 470kΩ 5% 1/4W Resistor

(yellow-violet-yellow-gold)

(see Figure A)

R12 - 220kΩ 5% 1/4W Resistor

(red-red-yellow-gold)

(see Figure A)

Figure C

Mount the transistor
with the flat side in
the same direction
as the marking on
the PC board as
shown.

Install the following parts. Then, mark a check þ in the box provided.

-5-

ASSEMBLY INSTRUCTIONS

Identify and install the following parts as shown. After soldering each part, mark a check þ in the box provided.
Be sure that solder has not bridged to an adjacent pad.

R21 - 900Ω .25% 1/4W Resistor

(white-black-black-black-blue)

(see Figure A)

D3 - 1N4007 Diode (see Fig. D)

R22 - 9kΩ .25% 1/4W Resistor

(white-black-black-brown-blue)

(see Figure A)

R23 - 90kΩ .25% 1/4W Resistor

(white-black-black-red-blue)

(see Figure A)

R24 - 117kΩ .5% 1/4W Resistor

(brown-brown-violet-orange-green)

(see Figure A)

R25 - 117kΩ .5% 1/4W Resistor

(brown-brown-violet-orange-green)

(see Figure A)

R35 - 117kΩ .5% 1/4W Resistor

(brown-brown-violet-orange-green)

(see Figure A)

R26 - 274kΩ .5% 1/4W Resistor

(red-violet-yellow-orange-green)

(see Figure A)

R27 - 274kΩ .5% 1/4W Resistor

(red-violet-yellow-orange-green)

(see Figure A)

R32 - 2kΩ Thermistor PTC

R20 - 100Ω .25% 1/4W Resistor

(brown-black-black-black-blue)

(see Figure A)

R8 - 9Ω .25% 1/4W Resistor
(white-black-black-silver-blue)

(see Figure A)

R10 - 0.99Ω .5% 1/4W Resistor

(black-white-white-silver-green)

Q1 - 9013 Transistor

(see Figure C)

R18 - 220kΩ 5% 1/4W Resistor

(red-red-yellow-gold)

(see Figure A)

R19 - 220kΩ 5% 1/4W Resistor

(red-red-yellow-gold)

(see Figure A)

Flat

r

Insert the narrow end of the three input sockets
into the PC board from the top legend, as shown in
Figure E. Solder the sockets to the PC board on
the component side only. The solder should extend
completely around the socket (see Figure E).

r

Insert the shunt wire (R9) into the PC board holes
from the component side as shown in Figure E. Adjust
the wire so that it sticks out the other (solder) side of
the PC board 1/8”. Solder the wire to the PC board on
the component side only. Cut excess leads flush.

r Be sure that the 8-pin transistor socket will slide

easily through its hole in the top case from either
direction. If it does not, carefully slide it through
the hole several times in each direction to remove
any burrs. Do not push on the socket leads or they
may be damaged.

r Insert the socket into the PC board holes from the

solder side as shown in Figure E. Be sure that the
tab lines up with the hole as shown in the figure.
Solder the socket to the PC board on the
component side of the PC board as shown in the
figure and cut off excess leads.

r

Feed the battery snap wires up through the holes
in the PC board from the solder side as shown in
Figure E. Insert the red wire into the hole marked
(9V+) and black wire into hole marked (9V–) as
shown. Solder the wires to the PC board.

r Insert the two fuse clips into the PC board holes

on the component side as shown in Figure E. Be
sure that the tabs are on the outside as shown in
the figure. Solder the clips to the PC board.

Top legend marking on PC board

Figure D

Stand diode on end. Mount
with band as shown on the top
legend.

Band

Top legend marking on
PC board