BEST BOOK ON HOW TO TEST ELECTRONIC COMPONENTS

BEST BOOK ON HOW TO TEST ELECTRONIC COMPONENTS

By Colin Mitchell

 SECTION ONE

This eBook shows you how to TEST COMPONENTS.

To do this you need "TEST GEAR."   The best item of Test Gear is a

MULTIMETER. It can test almost 90% of all components. And that's what wewill do in this eBook:

CONTENTS:

Analogue Multimeter

Multimeters

Audio Stages

Non-polar Capacitor(electrolytic)

Batteries- testing

"Open" Resistor- damaged

Burnt Resistor

Opto-couplers

Buying A Multimeter

Parallel- resistors

Capacitors

Piezo Diaphragms

Capacitors in Parallel

Piezo Buzzers

Cells- batteries

Potentiometers

Circuit Symbols

Pots- testing

Co-Ax Cables

Power Diodes

Colour Code (Resistor)

Relays

Coils

Remote Controls

Continuity

Resistor Colour Code

Creating any value of R

Resistor Networks

Current- measuring

Resistors- series

Damper Diodes

Schottky Diodes

Darlington Transistors

SCRs

Digital Chips

Symbols

Digital Multimeter

Signal Injector

Diodes

Silicon diodes

Earth Leakage Detectors

Soldering

Electrolytics

Spark Gaps

FETs

Super Probe MkII

Focus pots

Surface Mount- Packs

Fuses

Surface-Mount Resistors

Germanium Diodes

Surface-Mount Resistor Markings

Impedance- of a stage

Switches

IC's- also called Digital Chips

Testing A Circuit

IC's- Analogue Chips

Testing A Resistor

"In-Circuit" testing

Testing Components "In-Circuit"

Inductors

Transformers

Inductors- measuring

Transistor Outlines

Integrated Circuits

Transistors

Isolation Transformer

Triacs

LEDs

Unknown resistors- testing

Logic Probe MkIIB

Using A Multimeter

Logic Probe- Simple

Voltage Regulators

Logic Probe - using CD4001

Voltages on a circuit

Logic Probe - using CD4011

Yokes

Making your own components

Zener Diodes

Measuring Resistance

4-Band Resistors

Measuring Voltage

5-Band Resistors

Mica Washers and Insulators

MOSFETs

MULTIMETERS

There are two types:

DIGITAL and ANALOGUE

Digital Multimeterhas a set of digits on the display and an Analogue Multimeterhas a scale with a pointer (or needle).

You really need both types to cover the number of tests needed for designing andrepair-work.  We will discuss how they work, how to use them and some of the differences between them.

 

DIGITAL AND ANALOGUE MULTIMETERS

BUYING A MULTIMETER

There are many different types on the market.The cost is determined by the number of ranges and also the extra features such asdiode tester, buzzer (continuity), transistor tester, high DC current and others.

Since most multimeters are reliable and accurate, buy one with the greatest number ofranges at the lowest cost.

This article explains the difference between a cheap analogue meter, an expensiveanalogue meter and a digital meter. You will then be able to work out which twometers you should buy.

Multimeters are sometimes called a "meter",  a "VOM"  (Volts-Ohms-Milliamps or VoltOhm Meter) or "multi-tester" or even "a tester" - they are all the same.

USING A MULTIMETER

Analogue and digital multimeters have either a rotary selector switch or push buttonsto select the appropriate function and range. Some Digital Multimeter (DMMs) are auto-ranging; they automatically select the correct range of voltage, resistance, or currentwhen doing a test. However you need to select the function.

Before making any measurement you need to know what you are checking. If you aremeasuring voltage, select the AC range (10v, 50v, 250v, or 1000v) or DC range(0.5v, 2.5v, 10v, 50v, 250v, or 1000v). If you are measuring resistance, select the

Ohms range (x1, x10, x100, x1k, x10k). If you are measuring current, select theappropriate current range DCmA 0.5mA, 50mA, 500mA. Every multimeter is differenthowever the photo below shows a low cost meter with the basic ranges

 

ANALOG MULTIMETER

The most important point to remember is this:

You must select a voltage or current range that is bigger or HIGHER than themaximum expected value, so the needle does not swing across the scale and hit the"end stop."

If you are using a DMM (Digital Multi Meter), the meter will indicate if the voltage orcurrent is higher than the selected scale, by showing "OL" - this means "Overload." Ifyou are measuring resistance such as 1M on the x10 range the "OL" means "Open

Loop" and you will need to change the range.  Some meters show "1' on the displaywhen the measurement is higher than the display will indicate and some flash a set ofdigits to show over-voltage or over-current.  A "-1" indicates the leads should bereversed for a "positive reading."

If it is an AUTO RANGING meter, it will automatically produce a reading otherwise theselector switch must be changed to another range.

 

DIGITAL MULTIMETER

 

The Common (negative) lead ALWAYS fits intothe "COM " socket. The red lead fits into thered socket for Voltage and Resistance.

Place the red lead (red banana plug)into "A" (for HIGH CURRENT "Amps")or mA, uA for LOW CURRENT.

The black "test lead" plugs into the socket marked "-""Common", or "Com,"  and thered "test lead" plugs into meter socket marked "+" or "V-W-mA."   The third bananasocket measures HIGH CURRENT and the positive (red lead) plugs into this. You DONOT move the negative "-" lead at any time.

The following two photos show the test leads fitted to a digital meter. The probes andplugs have "guards" surrounding the probe tips and also the plugs so you can measurehigh voltages without getting near the voltage-source.

 

Analogue meters have an "Ohms Adjustment" to allow for the change in voltage of thebattery inside the meter (as it gets old)

 

"Ohms Adjust" is also called "ZERO SET"

The sensitivity of this meter is 20,000ohms/volton the DC ranges and 5k/v on the AC ranges.

Before taking a resistance reading (each time on any of the Ohms scales) you need to"ZERO SET" the scale, by touching the two probes together and adjust the pot until theneedle reads "0" (swings FULL SCALE). If the pointer does not reach full scale, thebatteries need replacing. Digital multimeters do not need "zero adjustment".